Lattice Shell Methodologies

Engineering Research Journal - Faculty of Engineering (Shoubra)

Parametric Design is a powerful design approach that has been widely applied to architectural design in recent years. Designers may create rules using parametric design tools that consider the aesthetics, functionality, and performance needs of a design. The purpose of the study is to analyze the impact of parametric design patterns in producing unique, well-structured, and aesthetic shell lightweight structures. Achieve that by firstly defining the shell lightweight structure, its types of geometries, and Objectives for form finding of the shell structure. Secondly defining the parametric design, Characteristics of the parametric design process, and parametric patterns. thirdly studying and analyzing different five distinct global examples, in terms of the structure's form-finding technique using parametric patterns, used materials, fabrications, and installation. Finally making an analytical comparison of the five examples to achieve the main objective of the study. From this analytical comparison find that the parametric design and parametric patterns has a critical role in form-finding shell lightweight structures.

Architectural Intelligence, 2023

Free-form architectural design has gained significant interest in modern architectural practice. Due to their visually appealing nature and inherent structural efficiency, free-form shells have become increasingly popular in architectural applications. Recently, topology optimization has been extended to shell structures, aiming to generate shell designs with ultimate structural efficiency. However, despite the huge potential of topology optimization to facilitate new design for shells, its architectural applications remain limited due to complexity and lack of clear procedures. This paper presents four design strategies for optimizing free-form shells targeting architectural applications. First, we propose a topology-optimized ribbed shell system to generate free-form rib layouts possessing improved structure performance. A reusable and recyclable formwork system is developed for their effective and sustainable fabrication. Second, we demonstrate that topology optimization can be combined with funicular form-finding techniques to generate a rich variety of elegant designs, offering new design possibilities. Third, we offer cost-effective design solutions using modular components for free-form shells by combining surface planarization and periodic constraint. Finally, we integrate topology optimization with user-defined patterns on free-form shells to facilitate aesthetic expression, exemplified by the Voronoi pattern. The presented strategies can facilitate the usage of topology optimization in shell designs to achieve high-performance and innovative solutions for architectural applications.

Journal of Civil Engineering, Environment and Architecture, 2014

The paper concerns geometrical shaping of shell structures composed of individual shells arranged effectively in space that is in a way similar to properties of a regular, geometrical surface with taking into account straight lines and planes normal to the base surface. The individual segments are made up of unidirectional folded flat sheets transformed into shell shapes. A freedom of transversal width increments of these sheets is assured while transforming, which ensures their possible small effortsuch a deformation of a material intended for transferring functional loads but which makes restrictions concerning the shell sheets shapes. These shape restrictions are provoked by the strictly determined stiffness characteristics of the shell sheets and cause of the edge or discontinuous areas between adjacent shellssegments in the shell structure. The method of delimiting great diversity of effective, compound shell forms whose general shapes are close to regular, geometrical surfaces characterized by any sign of the Gaussian curvature is presented. Innovation of the way also consists in integration of the form of a whole building object (walls and shell roof). It is achieved by division of the elevation walls into flat areas contained in planes close to planes normal to the base surface as accurate as possible. The segment's directrices are also contained in these planes. The presented issues are the ground for elaborating a method of shaping of the light gauge steel shell structures and their further integration with whole building objects.

2016

Statics Aware Voronoi Grid-shells have been recently introduced in the Architectural Geometry field. These are innovative grid-shells endowed with a polygonal topology, whose geometry is structurally optimized by means of a novel algorithm [PTP+ 15]. Although being structurally effective as proved in [TPP+ 16] and arguably aesthetically charming, so far these grid-shells have struggled to attract architects' interest. We propose a method to fabricate a mockup of the grid shell by using modern additive 3D printing and laser cutting technologies. We also show how the realised mockup can be used to perform a preliminary validation of the simulated static performances of the grid-shell structure.

International Journal of Electrical and Computer Engineering (IJECE), 2023

Gridshells are commonly known as structures with the shape and rigidity of a double curvature shell consisting of a grid, not a continuous surface. In recent decades, these structures have attracted significant attention. The impact of various geometric patterns on free form gridshell structures is investigated here to demonstrate the necessity of collaboration between structural and architectural characteristics in enhancing structure efficiency. To that goal, a framework is proposed where three shells are first designed, and then six geometric patterns are formed on them. The main factors for evaluation of gridshells are decreasing the steel weight as an economic index and decreasing the displacement as a structural index, also, finite element method is used for structurally analyzing the gridshells, and the generated gridshells are compared to each other based on the mentioned indices. For the optimization process, an approach is suggested to find the most optimum gridshell, then numerical results show the efficiency of the proposed alternative approach.

The research-prototype is a 4 x 5 x 2m, “topologically optimized” concrete shell that was designed and built in ten days. The prototype and this ensuing paper aim to extend the rich legacy of form-finding to adequately represent the complexities of scale, digital design systems and delivery mechanisms of contemporary architectural practice. They explore synergies in early design between architecture, structural engineering, and manufacturing.

Engineering Structures

The difficulty to construct mechanically optimal shells may limit the use of structural optimisation in practice. The objective of this paper is to propose a new parametric representation of doubly curved shapes suited for structural optimisation of architectural shells that inherently considers fabrication constraints. We focus on a common construction constraint: the covering of building envelopes with planar facets. This paper proposes to implement the so-called marionette technique as a Computer-Aided-Design tool that guarantees covering of free-form shapes with planar quadrilateral facets. General considerations on the size and nature of the optimisation space created with this method are made. It is demonstrated through different case-studies that the quality of the parametrisation for shape optimisation of shell structures is similar to the one offered by Bézier surfaces, an ubiquitous modelling technique. The proposed method conciliates thus fabrication and structural performance.

2011

In the 21st century, as free-form design grows in popularity, grid shells are becoming a universal structural solution, enabling the conflation of structure and skin (facade) into one single element (Kolarevic 2003). This paper presents some of the results of a comprehensive research project focused on the automated design and optimization of grid structures over some predefined free form shape, with the goal of generating a stable and statically efficient structure. It shows that by combining design and FEM software in an iterative, Genetic Algorithms-based optimization process, stress and deformation in grid shell structures can be significantly reduced, material can be saved and stability enhanced.

Metals

Lattice structures for engineering applications are patterns of unit cells designed to make a larger functional structure. Research on lattice structures ranges in many fields, from mechanical characterization and cell and pattern designs in respect of their applications, to the manufacturing process and its final shape control. From the manufacturing point of view, some kinds of lattice structures can be infeasible when approached with traditional manufacturing methods. It may offer an inevitable limitation of their adoption. However, advancements in Additive Manufacturing (AM) have solved this manufacturing issue to a great extent, allowing to obtain major complexity of the cells that can be achieved. The topology, shape of the unit cell, and the characteristics of its replication pattern allow us to obtain many kinds of structures in respect of the different engineering requirements and manufacturing constraints. Nevertheless, the necessity of new or dedicated CAD-CAE approaches ...

2017

This thesis focuses on surface articulation of a shell structure constructed through a generative, parametric, modular design process. The shell form uses vault topology that adapts to varying site conditions such as topography and shape and that serves as contemplative space. Contemplative and aesthetic qualities have been achieved by analyzing aspects of spatial vernacular muqarnas and emulating aspects of their geometry within new surface ornament. By abstracting muqarnas, and exploring aniconic character informed by both vernacular precedent and contemporary parametric design methods, the design offers a specialized new interpretation of this historical type of ornament. The design proposes an expandable master system. Two strategies based on this system are illustrated, both organized with similar components: columns (load-bearing modules) and bridges (modules for covering spans). Different behaviours are exhibited: first, symmetrical and homogeneous form and, second, non-symme...