Impact of nonlinearity on bolt forces in multi-bolted systems: a case of the assembly state
Proc. of the 22nd International Scientific Conference “MECHANIKA 2017“ (Birštonas, Lithuania, 19 May 2017), Kaunas, Kaunas University of Technology 2017, 110-113.
The paper deals with modelling and calculations of asymmetrical multi-bolted joints treated as a ... more The paper deals with modelling and calculations of asymmetrical multi-bolted joints treated as a system composed of four subsystems at the assembly stage. These subsystems are: a couple of joined elements, a contact layer between the elements, and a set of bolts. The contact layer is formed as the Winkler model, and the set of bolts are modeled using simplified beam models. The truth of the theorem has been tested, according to which nonlinearity of the contact layer has a negligible impact on the final values of the bolt forces in the case of sequential tightening of the multi-bolted joint.
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Papers by Rafał Grzejda
in remote surgery were analysed. Due to the fact that the final version of the drone is to take up the wounded without the participation of a third party, design aspects related to this are presented and examples of solutions are proposed.
interpretation. Temperature variations significantly influenced ultrasound signal characteristics, leading to observable changes in FBH indications, particularly at elevated temperatures. Increased ultrasound attenuation necessitated adjustments in decibel settings to maintain accuracy. SS 304
and SS 316 exhibited distinct responses to temperature changes, with SS 316 showing higher dB values and unique signal behaviors, including increased scattering and noise echoes at elevated temperatures. Detected depths for slots and FBHs correlated closely with designed depths, with
deviations generally less than 0.5 mm; however, some instances showed deviations exceeding 2 mm, underscoring the need for careful interpretation. At temperatures above 230 ◦C, the disbanding
of probe elements led to weak or absent signals, complicating data interpretation and requiring adjustments in testing protocols. This study highlights the feasibility and effectiveness of PACM for corrosion detection on hot SS surfaces, providing critical insights into material behavior under thermal conditions. Future research should include physical examination of samples using Scanning Electron Microscopy (SEM) to validate and enhance the reliability of the findings. The integration of non-contact NDT methods and optimization of calibration techniques are essential for improving PACM performance at elevated temperatures.
heavy machinery or equipment is presented. Connections made using different types of shims, with
particular emphasis on polymer–steel shims, are investigated. The stiffness characteristics for the
adopted models of multi-bolted foundation connections at the installation stage are described and
compared. It is shown that the use of polymer–steel shims can result in a significant improvement in
the stiffness of a multi-bolted foundation connection compared to a connection with a polymer shim,
and in achieving a multi-bolted foundation connection with a stiffness similar to that of a connection
with a steel shim (at a sufficiently low polymer layer thickness).
and dumping not only harm the environment but also jeopardize human health and safety. Recognizing the urgent need for sustainable waste management, researchers have increasingly focused on repurposing agricultural
plant waste as a valuable resource. This paper presents a comprehensive review of the potential of agricultural
plant waste in wealth creation and sustainable development. It highlights the detrimental impacts of current
disposal methods and emphasizes the necessity for alternative approaches. By analyzing the physical, mechanical, and chemical properties of plant fibers, particularly cellulose, hemicellulose, and lignin, this review underscores their suitability for diverse applications. Moreover, it explores the emerging trend of utilizing pineapple
leaf fiber, a sustainable and lightweight material, in structural applications, such as UAV construction. With its
exceptional mechanical properties and biodegradability, pineapple leaf fiber holds promise as a viable alternative to traditional materials, contributing to a more sustainable future. In conclusion, this review advocates for
a paradigm shift towards embracing agricultural plant waste as a valuable asset for economic prosperity and
environmental sustainability. It underscores the importance of continued research and technological advancements to unlock the full potential of agricultural waste in fostering a circular economy and driving sustainable
development globally.
in remote surgery were analysed. Due to the fact that the final version of the drone is to take up the wounded without the participation of a third party, design aspects related to this are presented and examples of solutions are proposed.
interpretation. Temperature variations significantly influenced ultrasound signal characteristics, leading to observable changes in FBH indications, particularly at elevated temperatures. Increased ultrasound attenuation necessitated adjustments in decibel settings to maintain accuracy. SS 304
and SS 316 exhibited distinct responses to temperature changes, with SS 316 showing higher dB values and unique signal behaviors, including increased scattering and noise echoes at elevated temperatures. Detected depths for slots and FBHs correlated closely with designed depths, with
deviations generally less than 0.5 mm; however, some instances showed deviations exceeding 2 mm, underscoring the need for careful interpretation. At temperatures above 230 ◦C, the disbanding
of probe elements led to weak or absent signals, complicating data interpretation and requiring adjustments in testing protocols. This study highlights the feasibility and effectiveness of PACM for corrosion detection on hot SS surfaces, providing critical insights into material behavior under thermal conditions. Future research should include physical examination of samples using Scanning Electron Microscopy (SEM) to validate and enhance the reliability of the findings. The integration of non-contact NDT methods and optimization of calibration techniques are essential for improving PACM performance at elevated temperatures.
heavy machinery or equipment is presented. Connections made using different types of shims, with
particular emphasis on polymer–steel shims, are investigated. The stiffness characteristics for the
adopted models of multi-bolted foundation connections at the installation stage are described and
compared. It is shown that the use of polymer–steel shims can result in a significant improvement in
the stiffness of a multi-bolted foundation connection compared to a connection with a polymer shim,
and in achieving a multi-bolted foundation connection with a stiffness similar to that of a connection
with a steel shim (at a sufficiently low polymer layer thickness).
and dumping not only harm the environment but also jeopardize human health and safety. Recognizing the urgent need for sustainable waste management, researchers have increasingly focused on repurposing agricultural
plant waste as a valuable resource. This paper presents a comprehensive review of the potential of agricultural
plant waste in wealth creation and sustainable development. It highlights the detrimental impacts of current
disposal methods and emphasizes the necessity for alternative approaches. By analyzing the physical, mechanical, and chemical properties of plant fibers, particularly cellulose, hemicellulose, and lignin, this review underscores their suitability for diverse applications. Moreover, it explores the emerging trend of utilizing pineapple
leaf fiber, a sustainable and lightweight material, in structural applications, such as UAV construction. With its
exceptional mechanical properties and biodegradability, pineapple leaf fiber holds promise as a viable alternative to traditional materials, contributing to a more sustainable future. In conclusion, this review advocates for
a paradigm shift towards embracing agricultural plant waste as a valuable asset for economic prosperity and
environmental sustainability. It underscores the importance of continued research and technological advancements to unlock the full potential of agricultural waste in fostering a circular economy and driving sustainable
development globally.