Topology Optimization for Discovery of Auxetic Origami Structures

2018 ◽  
Author(s):  
Andrew Gillman ◽  
Kazuko Fuchi ◽  
Alexander Cook ◽  
Alexander Pankonien ◽  
Philip R. Buskohl
Keyword(s):  
Topology Optimization ◽  
Modal Analysis ◽  
Design Space ◽  
Element Model ◽  
Mechanical Analysis ◽  
Poisson's Ratio ◽  
Objective Functions ◽  
Geometric Nonlinearities ◽  
Truss Element ◽  
The Many

Origami, as it moves from an art to a scientifically useful technology, enables a rich design space given the numerous bifurcations that exist off the flat state. In this work, we utilize origami as a platform for design of auxetic metamaterials and employ topology optimization for the automated robust discovery of these structures. In particular, the mechanical analysis is performed with an efficient and accurate nonlinear truss element model that captures the geometric nonlinearities associated with origami folding, and modal analysis off the flat state enables access to the many bifurcating branches of folding. Here, objective functions are explored that target a desired in-plane Poisson’s ratio. The Miura-ori fold pattern, a commonly studied flat-foldable pattern, is considered as a verification study for the framework presented.

Discovering Sequenced Origami Folding Through Nonlinear Mechanics and Topology Optimization

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Andrew S. Gillman ◽  
Kazuko Fuchi ◽  
Philip R. Buskohl
Keyword(s):  
Topology Optimization ◽  
Design Space ◽  
Optimization Algorithms ◽  
Element Model ◽  
Evolutionary Optimization ◽  
Nonlinear Mechanics ◽  
Design Problems ◽  
Mechanics Model ◽  
Highly Nonlinear ◽  
Evolutionary Optimization Algorithms

Origami folding provides a novel method to transform two-dimensional (2D) sheets into complex functional structures. However, the enormity of the foldable design space necessitates development of algorithms to efficiently discover new origami fold patterns with specific performance objectives. To address this challenge, this work combines a recently developed efficient modified truss finite element model with a ground structure-based topology optimization framework. A nonlinear mechanics model is required to model the sequenced motion and large folding common in the actuation of origami structures. These highly nonlinear motions limit the ability to define convex objective functions, and parallelizable evolutionary optimization algorithms for traversing nonconvex origami design problems are developed and considered. The ability of this framework to discover fold topologies that maximize targeted actuation is verified for the well-known “Chomper” and “Square Twist” patterns. A simple twist-based design is also discovered using the verified framework. Through these case studies, the role of critical points and bifurcations emanating from sequenced deformation mechanisms (including interplay of folding, facet bending, and stretching) on design optimization is analyzed. In addition, the performance of both gradient and evolutionary optimization algorithms are explored, and genetic algorithms (GAs) consistently yield solutions with better performance given the apparent nonconvexity of the response-design space.

Modal Analysis and Lightweight Design of High-Power Marine Gearbox Based on Topology Optimization

2013 ◽  
Vol 706-708 ◽  
pp. 1428-1432
Author(s):  
Ming Hong Yuan ◽  
Shui Guang Tong ◽  
Qin Cai
Keyword(s):  
Topology Optimization ◽  
Modal Analysis ◽  
High Power ◽  
Design Space ◽  
Lightweight Design ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Local Strength ◽  
Dynamic Performances ◽  
Design And Manufacture

Based on topology optimization, modal analysis and lightweight design of high-power marine gearbox case is studied. By the finite element analysis of original gearbox case, the structure strength has greater redundancy. After determining the design space and working load, after determining the design space and working load, the case thinning and local strength enhanced program based on SIMP method has determined. By considering the rationality and security of design and manufacture, both the static and dynamic performances of the optimized case is greatly improved, with a 16.36% reduction in maximum stress, a 13.86% reduction in maximum displacement, and successfully saving material 5.87%.

Structure Design and Mechanical Analysis on a Large Spaceborne Flat Seam Antenna

2014 ◽  
Vol 543-547 ◽  
pp. 291-294
Author(s):  
Wen Jie Fan ◽  
Xiao Peng Li ◽  
Ning Li
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Modal Analysis ◽  
Random Vibration ◽  
Element Model ◽  
Mechanical Analysis ◽  
Structure Design

Large spaceborne flat seam antennas boom recently. The structure design of the large flat seam antenna is introduced, and finite element model is built. The first frequency of antenna is obtained from modal analysis and it meet the requirement. The results of sine vibration and random vibration shows that strength satisfy the requirement and it has a certain margin.

Topology Optimization Design of High Pressure Storage Tank Structure

2012 ◽  
Vol 430-432 ◽  
pp. 828-833
Author(s):  
Qiu Sheng Ma ◽  
Yi Cai ◽  
Dong Xing Tian
Keyword(s):  
Finite Element ◽  
High Pressure ◽  
Topology Optimization ◽  
Storage Tank ◽  
Optimization Design ◽  
Influence Factors ◽  
Element Model ◽  
Design Variables ◽  
Calculation Results ◽  
Pressure Storage

In this paper, based on ANSYS the topology optimization design for high pressure storage tank was studied by the means of the finite element structural analysis and optimization. the finite element model for optimization design was established. The design variables influence factors and rules on the optimization results are summarized. according to the calculation results the optimal design result for tank is determined considering the manufacturing and processing. The calculation results show that the method is effective in optimization design and provide the basis to further design high pressure tank.

scholarly journals Numerical aspects for efficient welding computational mechanics

2014 ◽  
Vol 18 (suppl.1) ◽  
pp. 139-148
Author(s):  
Tarek Aburuga ◽  
Aleksandar Sedmak ◽  
Zoran Radakovic
Keyword(s):  
Residual Stresses ◽  
Three Dimensional ◽  
Shell Element ◽  
Element Model ◽  
Mechanical Analysis ◽  
Tensile Test Specimen ◽  
Integrity Assessment ◽  
Mass Scaling ◽  
Three Dimensional Models ◽  
Thermal Mechanical Analysis

The effect of the residual stresses and strains is one of the most important parameter in the structure integrity assessment. A finite element model is constructed in order to simulate the multi passes mismatched submerged arc welding SAW which used in the welded tensile test specimen. Sequentially coupled thermal mechanical analysis is done by using ABAQUS software for calculating the residual stresses and distortion due to welding. In this work, three main issues were studied in order to reduce the time consuming during welding simulation which is the major problem in the computational welding mechanics (CWM). The first issue is dimensionality of the problem. Both two- and three-dimensional models are constructed for the same analysis type, shell element for two dimension simulation shows good performance comparing with brick element. The conventional method to calculate residual stress is by using implicit scheme that because of the welding and cooling time is relatively high. In this work, the author shows that it could use the explicit scheme with the mass scaling technique, and time consuming during the analysis will be reduced very efficiently. By using this new technique, it will be possible to simulate relatively large three dimensional structures.

scholarly journals A new stress-based topology optimization approach for finding flexible structures

2021 ◽  
Author(s):  
Martin Noack ◽  
Arnold Kühhorn ◽  
Markus Kober ◽  
Matthias Firl
Keyword(s):  
Topology Optimization ◽  
Stress State ◽  
Design Space ◽  
Flexible Structures ◽  
Optimization Approach ◽  
Principal Stresses ◽  
Output Displacement ◽  
Design Concepts ◽  
Flexible Designs ◽  
Gauss Points

AbstractThis paper presents a new FE-based stress-related topology optimization approach for finding bending governed flexible designs. Thereby, the knowledge about an output displacement or force as well as the detailed mounting position is not necessary for the application. The newly developed objective function makes use of the varying stress distribution in the cross section of flexible structures. Hence, each element of the design space must be evaluated with respect to its stress state. Therefore, the method prefers elements experiencing a bending or shear load over elements which are mainly subjected to membrane stresses. In order to determine the stress state of the elements, we use the principal stresses at the Gauss points. For demonstrating the feasibility of the new topology optimization approach, three academic examples are presented and discussed. As a result, the developed sensitivity-based algorithm is able to find usable flexible design concepts with a nearly discrete 0 − 1 density distribution for these examples.

Towards the Multiobjective Optimisation of Gas Turbine Combustors

2006 ◽  
Author(s):  
S. G. Wyse ◽  
G. T. Parks ◽  
R. S. Cant
Keyword(s):  
Transfer Function ◽  
Tabu Search ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Design Space ◽  
Objective Functions ◽  
Multiobjective Optimisation ◽  
Gas Turbine Combustor ◽  
Linear Network ◽  
Good Design

Gas turbine combustor design entails multiple, and often contradictory, requirements for the designer to consider. Multiobjective optimisation on a low-fidelity linear-network-based code is suggested as a way of investigating the design space. The ability of the Tabu Search optimiser to minimise NOx and CO, as well as several acoustic objective functions, is investigated, and the resulting “good” design vectors presented. An analysis of the importance of the flame transfer function in the model is also given. The mass flow and the combustion chamber width and area are shown to be very important. The length of the plenum and the widths of the plenum exit and combustor exit also influence the design space.

scholarly journals Inverse Optimum Safety Factor Method for Reliability-Based Topology Optimization Applied to Free Vibrated Structures

2019 ◽  
pp. 8-19 ◽  
Author(s):  
Ghias Kharmanda ◽  
Imad R. Antypas ◽  
Alexey G. Dyachenko
Keyword(s):  
Topology Optimization ◽  
Structure Function ◽  
Modal Analysis ◽  
Safety Factor ◽  
Optimization Model ◽  
High Performance ◽  
Structural Type ◽  
Efficient Tool ◽  
Performance Levels ◽  
Reliability Level

Introduction. The classical topology optimization leads to a prediction of the structural type and overall layout, and gives a rough description of the shape of the outer as well as inner boundaries of the structure. However, the probabilistic topology optimization (or reliability-based topology optimization) model leads to several reliability-based topologies with high performance levels. The objective of this work is to provide an efficient tool to integrate the reliability-based topology optimization model into free vibrated structure. Materials and Methods. The developed tool is called inverse optimum safety method. When dealing with modal analysis, the choice of optimization domain is highly important in order to be able to eliminate material taking account of the constraints of fabrication and without affecting the structure function. This way the randomness can be applied on certain boundary parameters. Results. Numerical applications on free vibrated structures are presented to show the efficiency of the developed strategy. When considering a required reliability level, the resulting topology represents a different topology relative to the deterministic resulting one. Discussion and Conclusion. In addition to its simplified implementation, the developed inverse optimum safety factor strategy can be considered as a generative tool to provide the designer with several solutions for free vibrated structures with different performance levels.

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