Evolutionary topology optimization for structural compliance minimization considering design-dependent FSI loads

2017 ◽  
Vol 135 ◽  
pp. 44-55 ◽  
Author(s):  
R. Picelli ◽  
W.M. Vicente ◽  
R. Pavanello
Keyword(s):  
Topology Optimization ◽  
Compliance Minimization ◽  
Structural Compliance

Numerical Experiments in Using Voronoi Cell Finite Elements for Topology Optimization

2009 ◽  
Author(s):  
James M. Gibert ◽  
Georges M. Fadel
Keyword(s):  
Topology Optimization ◽  
Isotropic Material ◽  
Numerical Experiments ◽  
Voronoi Cell ◽  
Material Model ◽  
Topological Optimization ◽  
Advantages And Disadvantages ◽  
Compliance Minimization ◽  
Design Variables ◽  
Standard Linear

This paper provides two separate methodologies for implementing the Voronoi Cell Finite Element Method (VCFEM) in topological optimization. Both exploit two characteristics of VCFEM. The first approach utilizes the property that a hole or inclusion can be placed in the element: the design variables for the topology optimization are sizes of the hole. In the second approach, we note that VCFEM may mesh the design domain as n sided polygons. We restrict our attention to hexagonal meshes of the domain while applying Solid Isotropic Material Penalization (SIMP) material model. Researchers have shown that hexagonal meshes are not subject to the checker boarding problem commonly associated with standard linear quad and triangle elements. We present several examples to illustrate the efficacy of the methods in compliance minimization as well as discuss the advantages and disadvantages of each method.

An Adaptive Continuation Method for Topology Optimization of Continuum Structures Considering Buckling Constraints

2017 ◽  
Vol 09 (07) ◽  
pp. 1750092 ◽  
Author(s):  
Xingjun Gao ◽  
Lijuan Li ◽  
Haitao Ma
Keyword(s):  
Topology Optimization ◽  
Optimization Problems ◽  
Continuation Method ◽  
Optimization Process ◽  
Continuum Structures ◽  
Design Evolution ◽  
Buckling Constraints ◽  
Load Factors ◽  
Structural Compliance ◽  
Parameter Values

This paper presents an adaptive continuation method for buckling topology optimization of continuum structures using the Solid Isotropic Material with Penalization (SIMP) model. For optimization problems of minimizing structural compliance subject to constraints on material volume and buckling load factors, it has been found that the conflict between the requirements for structural stiffness and stability may have an adverse impact on the performance of existing optimization algorithms. An automatic scheme for adjusting the penalization parameter is introduced to deal with this conflict and thus achieves better designs. Based on an investigation on the effect of the penalization parameter on design evolution during the optimization process, a rule is established to determine the appropriate penalization parameter values. Using this rule, an effective scheme is developed for determining the penalization parameter values such that the buckling constraints are appropriately considered throughout the optimization process. Numerical examples are presented to illustrate the effectiveness of the proposed method.

scholarly journals Revisiting non-convexity in topology optimization of compliance minimization problems

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohamed Abdelhamid ◽  
Aleksander Czekanski
Keyword(s):  
Topology Optimization ◽  
Optimization Problems ◽  
Global Optimum ◽  
Continuation Methods ◽  
Comprehensive Treatment ◽  
Mathematical Treatment ◽  
Content Type ◽  
Compliance Minimization ◽  
Intermediate Density ◽  
Filtering Techniques

PurposeThis is an attempt to better bridge the gap between the mathematical and the engineering/physical aspects of the topic. The authors trace the different sources of non-convexification in the context of topology optimization problems starting from domain discretization, passing through penalization for discreteness and effects of filtering methods, and end with a note on continuation methods.Design/methodology/approachStarting from the global optimum of the compliance minimization problem, the authors employ analytical tools to investigate how intermediate density penalization affects the convexity of the problem, the potential penalization-like effects of various filtering techniques, how continuation methods can be used to approach the global optimum and how the initial guess has some weight in determining the final optimum.FindingsThe non-convexification effects of the penalization of intermediate density elements simply overshadows any other type of non-convexification introduced into the problem, mainly due to its severity and locality. Continuation methods are strongly recommended to overcome the problem of local minima, albeit its step and convergence criteria are left to the user depending on the type of application.Originality/valueIn this article, the authors present a comprehensive treatment of the sources of non-convexity in density-based topology optimization problems, with a focus on linear elastic compliance minimization. The authors put special emphasis on the potential penalization-like effects of various filtering techniques through a detailed mathematical treatment.

Application of topology optimization method for the gothic greenhouse design

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jalal Javadi Moghaddam ◽  
Davood Momeni ◽  
Ghasem Zarei
Keyword(s):  
Topology Optimization ◽  
Safety Factor ◽  
Structural Design ◽  
Volume Fraction ◽  
Design Method ◽  
Optimization Method ◽  
Content Type ◽  
Final Design ◽  
Structure Strength ◽  
Structural Compliance

Purpose This research presents a design method for designing greenhouse structures based on topology optimization. Moreover, the structural design of a gothic greenhouse is proposed in which its structural strength has been improved by using this proposed method. In this method, the design of the structure is done mathematically; therefore, in the design process, more attention can be focused on the constraint space and boundary conditions. It was also shown how the static reliability and fatigue coefficients will change as a result of the design of the greenhouse structure with this method. Another purpose of this study is to find the weakest part of the greenhouse structure against lateral winds and other general loads on the greenhouse structure. Design/methodology/approach In the proposed method, the outer surface and the allowable volume as a constraint domain were considered. The desired loads can be located on the constraint domain. The topology optimization was used to minimize the mass and structural compliance as the objective function. The obtained volume was modified for simplifying the construction. The changes in the shape of the greenhouse structure were investigated by choosing three different penalty numbers for the topology optimization algorithm. The final design of the proposed structure was performed based on the total simultaneous critical loads on the structure. The results of the proposed method were compared in the order of different volume fractions. This showed that the volume fraction approach can significantly reduce the weight of the structure while maintaining its strength and stability. Findings Topology optimization results showed different strut and chords composition because of the changes in maximum mass limit and volume fraction. The results showed that the fatigue was more hazardous, and it decreased the strength of structure nearly three times more than a static analysis. Further, it was noticed that how the penalty numbers can affect topology optimization results. An optimal design based on topology optimization results was presented to improve the proposed greenhouse design against destruction and demolition. Furthermore, this study shows the most sensitive part of the greenhouse against the standard loads of wind, snow, and crop. Originality/value The obtained designs were compared with a conventional arch greenhouse, and then the structural performances were shown based on standard loads. The results showed that in designing the proposed structure, the optimized changes increased the structure strength against the standard loads compared to a simple arch greenhouse. Moreover, the stress safety factor and fatigue safety factor because of different designs of this structure were also compared with each other.

Robust Topology Optimization Under Random Load Locations

2014 ◽  
Author(s):  
Trung B. Pham ◽  
Christopher Hoyle ◽  
Brian Bay
Keyword(s):  
Topology Optimization ◽  
Robust Design ◽  
Robust Design Optimization ◽  
Structural Topology ◽  
Random Load ◽  
Research Areas ◽  
Active Research ◽  
Nodal Displacements ◽  
Structural Compliance ◽  
Moving Asymptotes

Recent years have seen the emergence of topology optimization as one of the most active research areas of structural optimization, with a broad range of promising applications in engineering design. Uncertainty is ubiquitous in real-world situations, which affects design solutions profoundly. This paper proposes a method to integrate topology optimization of static continuum structures with robust design optimization under uncertain load positions. To model the robust design problem, a multi-objective optimization formulation is posed, in which both the expectancy and the standard deviation of the structural compliance are minimized with weighting factors. Next a density based method, called Solid Isotropic Material with Penalization, and the Method of Moving Asymptotes are employed to output the robust structural topology. Numerical examples implemented in Matlab are then utilized to illustrate the proposed method, investigate outcomes of the robust design methodology against deterministic one, and confirm that the resulting designs are robust. Nodal displacements are compared between robust and deterministic solutions.

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