Dynamic Analysis

The proposed 2005 edition of the National Building Code of Canada specifies dynamic analysis as the preferred method for computing seismic design forces and deflections, while maintaining the equivalent static force method for areas of low seismicity and for buildings with certain height limitations. Dynamic analysis procedures are categorized as either linear (elastic) dynamic analysis, consisting of the elastic modal response spectrum method or the numerical integration linear time history method, or nonlinear (inelastic) response history analysis. While both linear and nonlinear analyses require careful analytical modelling, the latter requires additional considerations for proper simulation of hysteretic response and necessitates a special study that involves detailed review of design and supporting analyses by an independent team of engineers. The paper provides an overview of dynamic analysis procedures for use in seismic design, with discussions on mathematical modelling of structures, structural elements, and hysteretic response. A discussion of the determination of structural period to be used in association with the equivalent static force method is presented.

This paper presents the theoretical basis for both static and dynamic numerical approaches to the elastic stability of a folding multi-layered truss. Both analyses are based on bifurcation theory and include geometrical nonlinearity. The dynamic analysis includes an allowance for contact between nodes. Comparisons are made between published experimental folding patterns and the patterns obtained from both numerical methods in which bifurcations are demonstrated as elastic unstable snap-through behaviour. Several folding patterns are identified during the elastic instability where the folding behaviour of the truss is shown to be a function of the initial geometry and velocity of the dynamic loading. The authors suggest that the understanding of the behaviour will be very useful for the development of light weight structures subject to dynamic loading based on the bifurcation static analysis and dynamic analysis (using both the displacement control method and the load control method). (I. Ario), [email protected] (A. Watson).

This paper describes the development of a methodology to import key products of the DoD Architecture Framework into an executable form to conduct a dynamic analysis of the Command and Control (C2) system or capability represented by the architecture. Dynamic analysis of these models enables a user to assess the impact of change and determine measures of performance and effectiveness. The research team successfully implemented the methodology in a demonstration that made a three-way link among a business process model, a communications network model, and a combat simulation representing the system's operational environment. We linked these models together via the Runtime Infrastructure (RTI) of the High Level Architecture (HLA). Basic HLA interactions that we established allowed key events in the combat simulation to initiate one or more business processes in the process model. As a business process proceeded in time, the process model requested from the communications model a de...

This study explores the effects of haptic feedback on performance and learning by human subjects executing a dynamic task. We present the results of experiments involving the control of a ball and beam. Human subjects perform position targeting of the ball through hand operation of the beam angle. In our dynamic analysis we discuss how this prototype task may be used to test the efficacy of various haptic feedback conditions. We obtain results for two conditions of haptic feedback, produced using two ball sizes, and apply various metrics to analyze performance. We also examine ordering effects that occur in the presentation of these haptic conditions. Our analysis and experimental findings indicate that the performance of a dynamic task is governed by the complexity of system dynamics and the magnitude of haptic feedback. Our results provide modest support to recommend exposure to a more complex, higher force-feedback task prior to the execution of a simpler lower feedback task.

Les analyses traditionnelles du marché du travail s'avèrent incapables d'expliquer le paradoxe apparent entre un taux de chômage relativement modéré dans un pays tel que le Pérou (environ 10%, taux peu sensible aux fortes fluctuations macro-économiques) et la perception d'une grave crise de l'emploi. Une explication possible pourrait résider dans le fait que cet indicateur statique en coupe instantanée ne mesure pas les flux élevés entre les situations d'emploi et d'inemploi. Pour analyser ces questions, il est nécessaire de conduire une analyse dynamique sur données de panel. Nous avons ainsi construit un panel national d'individus en âge de travailler pour la période 1997-1999 à partir de l'enquête péruvienne auprès des ménages (ENAHO). Comme d'autres études réalisées dans des pays en développement, nous constatons qu'il existe une importante mobilité de l'emploi au Pérou. Nous trouvons également que la plupart des transitions interviennent entre emploi et inactivité plutôt qu'entre emploi et chômage. Le taux de chômage permanent apparaît très faible et le chômage serait donc essentiellement un phénomène frictionnel. Pour aller plus loin, nous avons élaborés des profils de transition inconditionnels, incluant les caractéristiques individuelles et du ménage, telles que le genre, l'âge, et le niveau d'éducation, associé avec chaque état de transition. Finalement, après avoir examiné ces transitions sur le marché du travail et les biais de sélection possibles, nous avons estimé un modèle logit multinomial. Ce modèle nous a permis d'apprécier l'incidence (conditionnelle) des caractéristiques individuelles et des ménages ainsi que des différents chocs sur les états de transition en matière d'emploi.

This paper proposes a new type of jetting dispenser driven by a piezostack actuator. After describing structural components of the dispensing mechanism and operating principle, a dynamic model of the dispenser is analytically formulated by considering dynamic behaviors of the piezostack-piston head and the ball-needle. The inelastic impact between the ball-needle and the ball-seat during dispensing process is also considered in the modeling. An analytical fluid-solid interaction model is then derived by integrating the dynamic behavior of the dispensing fluid. Dispensing performances such as dot size and flow rate are evaluated under various frequencies and amplitudes of the sinusoidal driving voltage applied to the piezostack actuator.

An object-oriented event-driven virtual environment (VE) for viewing the simulation results of¯exible multibody systems (FMS) is developed. The VE interfaces with the following output devices: immersive stereoscopic screen(s) and stereo speakers; and a variety of input devices including, head tracker, wand, joystick, mouse, microphone, and keyboard. The VE incorporates the following types of primitive software objects: user-interface objects, support objects, geometric entities, and ®nite elements. Each object encapsulates a set of properties, methods, and events that de®ne its behavior, appearance, and functions. A ªcontainerº object allows grouping many objects into one object, which inherits the properties of its ªchildrenº objects. The VE allows real-time viewing and ª¯y-throughº of photo-realistic models, vibrational mode-shapes, and animation of the dynamic motion of FMS. An application of this VE is presented for visualization of the dynamic analysis results of a large deployable space structure Ð NASA's Next Generation Space Telescope. Published by Elsevier Science Ltd.

Telecommunication towers are among the few steel structures that little attention has been paid to their seismic behavior in existing design codes. Due to lack of design provisions, the designers apply the existing building design codes to telecommunication towers. However, the seismic behavior and response of telecommunication towers is very different from that of building structures. For example, the base shear values obtained for telecommunication towers using the building codes is much higher than what it actually is. In this research, for obtaining the seismic amplification factors, ten of the existing self-supporting four-legged telecommunication towers in Iran with heights ranging from 18 to 67 meters are selected. Then, strong motion earthquakes are applied to these towers in both vertical and horizontal directions. By performing linear dynamic analysis, the base shear and vertical response of the towers are calculated. Dividing the obtained base shear or the vertical response by the product of the tower mass and maximum horizontal and/or vertical acceleration components will result in seismic amplification factors of both horizontal and vertical earthquake components. At the end, by drawing the amplification factors versus the fundamental flexural mode and the first axial mode of the towers, relations for estimating the base shear and the vertical response of the telecommunication towers are obtained.

JavaScript-based applications are very popular on the web today. However, the lack of effective protection makes various kinds of privacy violation attack possible, including cookie stealing, history sniffing and behavior tracking. There have been studies of the prevalence of such attacks, but the dynamic nature of the JavaScript language makes reasoning about the information flows in a web application a challenging task. Previous small-scale studies do not present a complete picture of privacy violations of today's web, especially in the ...

A significant number of existing reinforced-concrete bridges all over the world require maintenance and repair. Hence, the need for a rapid evaluation procedure for the diagnosis of existing bridges. This paper presents the application of a dynamic analysis methodology for structural evaluation of reinforced-concrete bridges. The methodology is based on the application of ambient vibrations non-destructive testing method and the identification of the structure total response using finite element method. A case study of a three span reinforced concrete bridge in a strong seismic activity area in the north of Algeria is analysed. The ambient vibration testing was carried out on the bridge, before and after its repair by the application of carbon fibre composites. The tests were conducted using an acquisition system made up of four accelerometers with three components placed at specific locations on the bridge. The finite element model gave comparable results to the experimental ambient vibrations tests. The modal parameters of the bridge before and after repair were identified by this in situ testing. The application of composite material to strengthen the structure increases the transverse rigidity of the structure and thus its modal frequency.

This paper investigates the dynamic characteristics of pulley systems with different numbers of bolt holes. Models with four, six and eight bolt holes were chosen for the pulley. Three sets of cyclic pressure were applied to the pulley system to resemble the different running revolutions of an engine. The study investigates the effect of the number of holes on the system’s stiffness and natural frequency. Finite element models were used to simulate the obtained deformations, stresses and frequency response function (FRF) for pulley models comprising four, six and eight bolt holes under different cyclic pressures. The results show that the stiffness and natural frequency increased with increasing the number of the bolt holes. This in turn, reduced the resulted deformations and stresses.
Recommended Citation
Asker, Haval Kamal and Dawood, Thaker Saleh (2020) "On The Dynamic Behaviour of Automobile Pulleys Under Cyclic Loading," Karbala International Journal of Modern Science: Vol. 6 : Iss. 2 , Article 12.
Available at: https://doi.org/10.33640/2405-609X.1603

Today almost all organizations have improved their performance through allowing more information exchange within their organization as well as between their distributers, suppliers, and customers using web support. Databases are central to the modern websites as they provide necessary data as well as stores critical information such as user credentials, financial and payment information, company statistics etc. These websites have

System evolution depends greatly on the ability of a maintainer to locate source code that is specific to feature implementation. Existing feature location techniques require either exercising several features of the system, or rely heavily on domain experts to guide the feature location process. In this paper, we present a novel approach for feature location that combines static and dynamic analysis techniques. An execution trace is generated by exercising the feature under study (dynamic analysis). A component dependency graph (static analysis) is used to rank the components invoked in the trace according to their relevance to the feature. Our ranking technique is based on the impact of a component modification on the rest of the system. The proposed approach is automatic to a large extent relieving users from any decision that would otherwise require extensive domain knowledge of the system. A case study is presented to support and evaluate the applicability of our approach.

This study investigates the potential for incorporating the elastic mechanisms found in fish propulsive systems into mechanical systems for the development of underwater propulsion. Physical and kinematic information associated with the steady swimming of the bonito and other scombrid species was used for the design. Several electroactive materials were examined for simulating muscle behavior and their relative suitability was compared. A dynamic analysis method adapted for muscle, which is a work-loop technique, would provide valuable information. However, the lack of such information on engineering materials made any direct comparison between the biological and mechanical systems difficult. Based on available information, nickel-titanium shape memory alloy (SMA) was better suited to produce relatively slow and powerful steady swimming of scombrid species. The simplified geometry of muscular systems and axial tendons was adapted. These arrangements alleviate the limited strain of the SMA by trading force for distance and provide an effective force transmission pathways to the backbone.

The network model approach for rigid and multi-rigid body systems developed recently [1,2] can also be used conveniently in formulating system equations or equations of motion of three-dimensional mechanical systems of interconnected rigid bodies. In this article, this method is further elaborated for establishing only the kinematics of spatial robotic bevel-gear trains. However the dynamic analysis of such systems using the same method is also possible and will be taken up in a future publication.

Structural models of large space structures have a substantial number of degrees of freedom (DOF) and possess semi-positive-definite stiffness matrices. The paper presents an efficient co-ordinate reduction procedure for structural dynamic analysis of large space structures. The method is based on the superposition of load-dependent Ritz vectors, which are computed in block form using a shifted stiffness matrix. Comparative transient dynamic analyses are performed on a 2803 DOF model of the space station Freedom using the load-dependent method (LDM) and the mode-displacement method (MDM) based on the superposition of eigenvectors. It is shown that the LDM is able to provide convergence of displacements with a small number of vectors. The acceleration response is found to be more sensitive to vector truncation than the displacement response. Error norms based on the representation of the dynamic load by the vector basis are developed to provide an indication of the effect of vector truncation on the structural response.

An unusually large number of minarets, which are slender tower structures, collapsed during the 1999 Kocaeli and Duzce, Turkey earthquakes with resulting damage to surrounding buildings and loss of life. The potential effects of the subsequently observed poor reinforcement detailing on the dynamic response is discussed. The probable cause of the extensive damage to reinforced concrete minarets is investigated by studying the observed failure modes and their seismic performance, and through the dynamic analysis of a representative minaret. The effects of spiral stairs, door openings, and balconies on the dynamic behavior are examined. The maximum dynamic internal force demands were compared with the calculated capacities. The locations of the maximum axial, shear, and flexural demands predicted from the finite element analysis of the minaret model were consistent with the earthquake damage observed at those critical locations.

The prevalence of the smart phones, the large market share of android and the openness of the android market make android more sensitive platform for malware attacks. For understanding the threat to security and privacy it is important to analyze the behavior of the malicious application. For a forensic point of
view an analyst need to understand the behavior of the application to find out the suspicious application In
this paper, we are focusing on a different type of android malware analysis techniques: static analysis, dynamic analysis and hybrid analysis (combination of static and dynamic analysis). This paper also presence different methods of these analyses along with their functionality and working.Comparisons of these analyses have been done along with their advantages and disadvantages.

Applying method of Lagrange multipliers, an attempt has been made to derive mathematical formulation to workout optimal purchasing policy in order to maximize utility of an individual consumer subject to multiple constraints; in this particular illustration, two constraints: 1) budget constraint, and 2) coupon constraint. An explicit example is given in order to examine the behaviour of an individual consumer and to support the analytical arguments, using comparative static analysis.

The dynamics of an electromechanically actuated metal V-belt (Empact) CVT is analyzed by studying a simplified linear model of the actuation system and a driveline model which includes the slip dynamics of the variator. The actuation system shows several CVT ratio depending modes. Linearization of the slip dynamics shows that the location and, moreover, the damping of the modes depends significantly on the amount of slip in the variator. Using pole-zero locations of the system it is shown that due to high overclamping a coupling between the primary and secondary side of the variator occurs with very large damping and due to underclamping the input and output sides of the variator are decoupled with low or even negative damping, resulting in an unstable system. Furthermore non-minimum phase behavior of the actuation is described. Using identification results from a non-linear model of the Empact CVT the interaction of the actuation and driveline dynamics is analyzed. Finally, measurements on a prototype of the Empact show similar behavior, however with very large damping of all of the modes.

During the last two decades materials, that exhibit graded properties, left their spirit of conceptual laboratory specimens to become a technological reality with a well established background. However structural applications of these materials are not a fulfilled research. Models of straight and curved beams are normally reported in the scientific literature as the easiest way to understand some existing aspects in mechanics of structures. Most of these models are formulated appealing to numerical approaches such as the finite element method among others, without taking into account theoretical aspects that can be quite useful to reduce algebraic complexity.

Islamic equity portfolios work with a smaller investment universe given the filtering of non-Shari'ah compliant stocks. It has been theoretically argued that this culminates in suboptimal portfolio diversification which in turn adversely affects risk-adjusted returns. We employ a number of methods, namely construction of efficient frontiers, time-varying maximum Sharpe ratios, MGARCH-DCC and analysis of covariance (ANCOVA), to offer empirical evidence that such a conceived portfolio diversification "penalty" is far from a foregone conclusion, at least empirically. Our results show that Islamic portfolios are not invariably handicapped in terms of portfolio diversification. We also explored dimensions which may account for differences in relative investment performance between Islamic and conventional portfolios such as portfolio constraints, length of investment horizon and market conditions. We believe this paper is among the first to apply substantial empirical analysis of the portfolio diversification perspective on Islamic equity investments.

A problem arises in the maintenance of large systems when the links between the specification based test cases and the code components they test are lost. It is no longer possible to perform selective regression testing because it is not known which test cases to run when a particular component is corrected or altered. To regain that knowledge, it is necessary to restore the links between test cases and code. This paper describes two complementary approaches to achieving that goal of reverse engineering -one by static analysis and the other by dynamic analysis. The objective in both cases is to determine which test cases exercise which methods in which components in order to enable selective regression testing.

During the 1989 Loma Prieta earthquake, accelerometers maintained by the California Division of Mines and Geology Strong Motion Instrumentation Program (CSMIP) recorded the response of a IO-story, reinforced-concrete building located in San Jose, California. In this paper, a computationally efficient, approximate, dynamic analysis of the building is conducted utilizing a reduced-order continuum model. Continuum methodology makes use of the repetitive nature of lattice framing systems to generate finite element models having significantly fewer degrees of freedom than models generated using classical discrete finite element techniques. The vibrational characteristics of the continuum model, as well as the results of dynamic analyses, are compared to information gained from the recorded response of the building. The continuum model proves to be quite accurate, both in capturing the dominant periods of vibration of the structure and in predicting the time-history response. As a result, the method shows promise as a tool for use in the analysis and design of large lattice structures subjected to earthquake loads.

This paper presents a novel analytical formulation of an element removal algorithm based on dynamic equilibrium and the resulting transient change in system kinematics, by applying imposed accelerations instead of external forces at a node where an element was once connected. The algorithm is implemented into an open-source finite element code, numerically tested using a benchmark structural system with simplified element removal criteria, and able to capture the effect of uncertainty in member capacity. Realistic element removal criteria are introduced for mode-dependent gravity load collapse of seismically deficient and retrofitted reinforced concrete (RC) columns and unreinforced masonry (URM) infill walls. Two applications are conducted using structural systems of RC frames with URM infill walls. The first is a probabilistic study of a one-story model subjected to an ensemble of 14 ground motion recordings from similar neighboring sites during an earthquake event. The study produces empirical probability curves for partial and complete collapse conditioned on different hazard levels, and concludes that the intra-event variability is a major source of uncertainty affecting the outcome of progressive collapse simulations. The second application is a deterministic sensitivity study of progressive collapse response in a five-story structural model to uncertainty in live load, stiffness, damping, and seismic hazard level, subjected to one ground motion record. The analysis identifies the time at incipient collapse as an adequate sensitivity measure, and the uncertainty in ground motion intensity as the most important, followed by the stiffness of the URM infill wall. Copyright © 2009 John Wiley & Sons, Ltd.

As software evolves, impact analysis estimates the potential effects of changes, before or after they are made, by identifying which parts of the software may be affected by such changes. Traditional impact-analysis techniques are based on static analysis and, due to their conservative assumptions, tend to identify most of the software as affected by the changes. More recently, researchers have begun to investigate dynamic impact-analysis techniques, which rely on dynamic, rather than static, information about software behavior. Existing dynamic impact-analysis techniques are either very expensive-in terms of execution overhead or amount of dynamic information collected-or imprecise. In this paper, we present a new technique for dynamic impact analysis that is almost as efficient as the most efficient existing technique and is as precise as the most precise existing technique. The technique is based on a novel algorithm that collects (and analyzes) only the essential dynamic information required for the analysis. We discuss our technique, prove its correctness, and present a set of empirical studies in which we compare our new technique with two existing techniques, in terms of performance and precision.

A solution is demonstrated to an infinite-horizon, discrete-time utility model describing the consumption and cutting behavior of a nonindustrial private landowner who is managing a multiple age-class forest and who values both consumption derived from harvesting the trees and amenity derived from the standing trees. A policy rule is derived to attain a normal forest from any initial age-class distribution. It is demonstrated that a noncyclical forest allowing a constant periodic harvest is typically not a normal forest. Therefore, an even-flow timber harvesting is not tied to the existence of a normal forest structure.

The inclusion of analytical and experimental models in biomechanical studies leads to the obtainment of important data for the research concerning the human skeleton, its traumas and diseases. The paper showcases a number of results regarding the static and dynamic analysis of some biomechanical components by using the finite element method (FEM). Models, representing parts of the human upper limb, have been studied using static trials. Considering the fact that we wish to emphasize the way in which such analyses can be done with a finite element method, we shall present only a few relevant examples for which we have experimental data, namely: analysis of the compression, bending and stretching of the humerus and bending of the radius and the ulna.

A homogenization method is presented for dynamic analysis of truss structures motivated by large satellite applications. The proposed method was previously compared to a full finite element procedure and the experimental verification of the homogenization approach is presented here. Local strains in a planar truss are found in terms of the strain components evaluated at the center of the repeating truss element. Kinetic and strain energy expressions are then derived in terms of the spatial and time derivative of the displacement components at the center of the truss element. Necessary assumptions are made to reduce the order of the strain field of the full model to a geometrically reduced order model. Hamilton's principle is employed to find the governing partial differential equations of motion for the equivalent continuum model. It is shown that the dynamic equations for this structure are similar to those of an anisotropic Timoshenko beam theory. Finally the natural frequencies of the structure are found using the one-dimensional homogenized model. A truss structure was fabricated and tested for the purpose of validation of the developed theory. The results for the frequency response functions and the natural frequencies from the continuum model are shown to be in good agreement with the experiment. As a result, the method shows promise as a tool for use in the analysis and design of lattice structures.

Online social games are Internet-based games that use the social networks formed by players to extend in-game functionality. For example, gamers participating in the BBO Fans community combine online bridge play with social networking. Despite an increase in the popularity of online social gaming-currently, there exist over one million online bridge players-, and of decades of research on social networks, the activity characteristics and the community structure of online social gaming remain relatively unknown. In this work we investigate and contrast these aspects for two bridge communities, BBO Fans (online) and Locomotiva (face to face). We propose the use of playing relationships instead of traditional social relationships such as friends and friends-of-friends. Using long-term, large-scale data we have collected from both the online and face to face bridge communities, we analyze user behavior, social network structure, and playing style in bridge communities. We find many similar characteristics in the two studied communities, but we also find more variation in the activity levels and fewer stable partnerships for the face to face bridge community.

In this paper we will solve some linear programming problems by solving systems of differential equations using game theory. The linear programming problem must be a classical constraints problem or a classical menu problem, i.e. a maximization/minimization problem in the canonical form with all the coefficients (from objective function, constraints matrix and right sides) positive. Firstly we will transform the linear programming problem such that the new problem and its dual have to be solved in order to find the Nash equilibrium of a matriceal game. Next we find the Nash equilibrium by solving a system of differential equations as we know from evolutionary game theory, and we express the solution of the obtained linear programming problem (by the above transformation of the initial problem) using the Nash equilibrium and the corresponding mixed optimal strategies. Finally, we transform the solution of the obtained problem to obtain the solution of the initial problem. We make als...

Pain caused by nerve injury (i.e. neuropathic pain) is associated with development of neuronal hyperexcitability at several points along the pain pathway. Within primary afferents, numerous injury-induced changes have been identified but it remains unclear which molecular changes are necessary and sufficient to explain cellular hyperexcitability. To investigate this, we built computational models that reproduce the switch from a normal spiking pattern characterized by a single spike at the onset of depolarization to a neuropathic one characterized by repetitive spiking throughout depolarization. Parameter changes that were sufficient to switch the spiking pattern also enabled membrane potential oscillations and bursting, suggesting that all three pathological changes are mechanistically linked. Dynamical analysis confirmed this prediction by showing that excitability changes co-develop when the nonlinear mechanism responsible for spike initiation switches from a quasi-separatrix-crossing to a subcritical Hopf bifurcation. This switch stems from biophysical changes that bias competition between oppositely directed fast-and slow-activating conductances operating at subthreshold potentials. Competition between activation and inactivation of a single conductance can be similarly biased with equivalent consequences for excitability. ''Bias'' can arise from a multitude of molecular changes occurring alone or in combination; in the latter case, changes can add or offset one another. Thus, our results identify pathological change in the nonlinear interaction between processes affecting spike initiation as the critical determinant of how simple injury-induced changes at the molecular level manifest complex excitability changes at the cellular level. We demonstrate that multiple distinct molecular changes are sufficient to produce neuropathic changes in excitability; however, given that nerve injury elicits numerous molecular changes that may be individually sufficient to alter spike initiation, our results argue that no single molecular change is necessary to produce neuropathic excitability. This deeper understanding of degenerate causal relationships has important implications for how we understand and treat neuropathic pain.

The estimation of response parameters plays an important role in the design of offshore structure. The periodic inspection and monitoring of offshore platforms for certification needs the study of the responses of structures owing to wave and wind forces. The complex dynamic behavior of the platform to the environmental loads makes it difficult to calculate exactly the dynamic responses. The present need of the industry is to have a time saving and accurate calculation methods, which can be in good agreement with the actual response parameters.

In this paper we are interested in the study of the dynamic behavior of a planar flexible slider-crank mechanism with clearance. Simulation and experimental tests were carried out for this goal. For the simulation tests, we have built the model under the software ADAMS. We used a contact model based on the so called Impact-function. An experimental set-up was designed and built to achieve some experimental validations. The presented results show that, in the presence of clearance, the mechanism responses were greatly influenced. The motion is characterized by the occurrence of three phases: a free motion, a continuous contact motion and an impact motion. In this paper, both the case of the mechanism with rigid link and the case with flexible link were studied. It is shown that in the presence of clearance, the coupler flexibility has a role of suspension for the mechanism.

This paper is concerned with an application of multibody techniques to the dynamic analysis of the tripode joint. The purpose of the mathematical model developed is the computation of all the constraint forces. In fact, the results of this investigation are preliminary for a study on the influence of geometry and inertia design parameters on the noise and vibrations caused by the joint.

Incremental dynamic analysis (IDA) is a widely used method for assessing structural performance under earthquake excitations. It enables direct evaluation of the record-to-record variability in structural response through a set of ground-motion records. If the number of ground-motion records is large then, the method becomes computationally demanding. To facilitate its practical application, a precedence list of ground-motion records has been introduced, aiming at selecting the most representative ground-motion records for IDA analysis. In progressive IDA analysis, the IDA curves are computed progressively, starting from the first ground-motion record in the precedence list. After an acceptable tolerance has been achieved, the analysis is terminated. This approach may significantly reduce the computational effort for first-mode-dominated structures, since the seismic response can be computed only for a certain number of ground-motion records from the precedence list to achieve an acceptable level of confidence in the prediction of the summarized (16th, 50th, and 84th fractiles) IDA curves. The proposed implementation of incremental dynamic analysis, which is demonstrated using an example of a 4-story reinforced concrete frame, can also be used for the selection of ground-motion records from a very large set of records, provided that all the records properly represent the seismic scenario for a given site.

The purpose of this paper is to show through the concrete example of epileptic seizure anticipation how neuro-dynamic analysis (using new mathematical tools to detect the dynamic structure of the neuro-electric activity of the brain) and ''pheno-dynamic'' analysis (using new interview techniques to detect the pre-reflective dynamic micro-structure of the corresponding subjective experience) may guide and determine each other. We will show that this dynamic approach to epileptic seizure makes it possible to consolidate the foundations of a cognitive non pharmacological therapy of epilepsy. We will also show through this example how the neuro-phenomenological co-determination could shed new light on the difficult problem of the ''gap'' which separates subjective experience from neurophysiological activity.

Feng et al. [Z.Q. Feng, F. Peyraut, N. Labed, Solution of large deformation contact problems with friction between Blatz-Ko hyperelastic bodies, Int. J. Eng. Sci. 41 (2003) 2213-2225] have proposed a study of contact problems between Blatz-Ko hyperelastic bodies in static cases using the bi-potential method. The extension of this method for dynamic analysis of impact problems is realized in the present work. The total Lagrangian formulation is adopted to describe large strains and large displacements non-linear behavior. A first order algorithm is applied for the numerical integration of the time-discretized equation of motion. Numerical examples are carried out in two cases: rigid-deformable and deformable-deformable-rigid impacts in 2D. Numerical results show that the proposed approach is robust and efficient and the physical energy dissipation phenomena are apparently illustrated.

We present a novel dynamic analysis technique that finds real deadlocks in multi-threaded programs. Our technique runs in two stages. In the first stage, we use an imprecise dynamic analysis technique to find potential deadlocks in a multi-threaded program by observing an execution of the program. In the second stage, we control a random thread scheduler to create the potential deadlocks with high probability. Unlike other dynamic analysis techniques, our approach has the advantage that it does not give any false warnings. We have implemented the technique in a prototype tool for Java, and have experimented on a number of large multi-threaded Java programs. We report a number of previously known and unknown real deadlocks that were found in these benchmarks.

A nonlinear dynamic analysis, including soil-structure interaction, is developed to estimate the seismic response characteristics and to predict the earthquake response of cable-stayed bridge towers with spread foundation. An incremental iterative finite element technique is adopted for a more realistic dynamic analysis of nonlinear soil-foundation-superstructure interaction system under great-earthquake ground motion. Two different approaches to model soil foundation interaction are considered: nonlinear Winkler soil foundation model and linear lumpedparameter soil model. The numerical results show that the simplified lumped-parameter-model analysis provides a good prediction for the peak response, but it overestimates the acceleration response and underestimates the uplift force at the anchor between superstructure and pier. The soil bearing stress beneath the footing base is dramatically increased due to footing base uplift. The predominant contribution to the vertical response at footing base resulted from the massive foundation rocking rather than from the vertical excitation.