An effective members-adding method for truss topology optimization based on principal stress trajectories

2017 ◽  
Vol 34 (6) ◽  
pp. 2088-2104 ◽  
Author(s):  
Ge Gao ◽  
Yaobin Li ◽  
Hui Pan ◽  
Limin Chen ◽  
Zhenyu Liu
Keyword(s):  
Topology Optimization ◽  
Principal Stress ◽  
Large Scale ◽  
Truss Topology Optimization ◽  
Force Transmission ◽  
Ground Structure ◽  
Element Analysis ◽  
Content Type ◽  
Truss Topology ◽  
Nodal Displacements

Purpose The purpose of this paper is to provide an effective members-adding method for truss topology optimization in plastic design. Design/methodology/approach With the help of the distribution of principal stress trajectories, obtained by finite element analysis of the design domain, ineffective zones for force transmission paths can be found, namely, areas whose nodes may have ersatz nodal displacements. Members connected by these nodes are eliminated and the reduced ground structure is used for optimization. Adding members in short to long order and limiting the number of members properly with the most strained ones added, large-scale truss problems in one load case and multiple-load cases are optimized. Findings Inefficient members (i.e. bars that fulfil the adding criterion but make no contribution to the optimal structure) added to the ground structure in each iterative step are reduced. Fewer members are used for optimization than before; therefore, faster solution convergence and less computation time are achieved with the optimized result unchanged. Originality/value The proposed members-adding method in the paper can alleviate the phenomenon of ersatz nodal displacements, enhance computational efficiency and save calculating resources effectively.

scholarly journals Applications of truss topology optimization in the design of reinforced concrete structures using „Strut and Tie” models

2013 ◽  
Vol 12 (1) ◽  
pp. 091-098
Author(s):  
Karol Bołbotowski ◽  
Michał Knauff ◽  
Tomasz Sokół
Keyword(s):  
Topology Optimization ◽  
Reinforced Concrete ◽  
Truss Topology Optimization ◽  
Ground Structure ◽  
Structure Approach ◽  
Strut And Tie ◽  
Truss Topology ◽  
Practical Design ◽  
The Cost ◽  
Ground Structure Approach

Although Strut and Tie models are often used in practical design due to their apparent concept based on truss analysis, the creation of a model consistent with behaviour of the real structure is not an easy task. Frame corner model considered in the paper and presented in code [7] and article [8] exemplifies the problem. The authors proposed a method of automatic generating of ST models by making use of truss topology optimization (volume minimization problem). The method is based on classical ground structure approach. The authors introduced a method of including the cost of nodes in the objective function, which allowed to obtain solutions consisting of rationally small number of bars (unlike Michell’s structures). Moreover, algorithms ensuring consistency with Eurocode requirements were developed. The method was implemented in computer program. With the use of the software the authors proposed an alternative ST model for the frame corner, which requires considerably less reinforcement steel in comparison with the model suggested by the code. The versatility of the program was well proven in several other examples of plane stress problems in reinforced concrete design.

A new method to generate the ground structure in truss topology optimization

2016 ◽  
Vol 49 (2) ◽  
pp. 235-251 ◽  
Author(s):  
Ge Gao ◽  
Zhen-yu Liu ◽  
Yao-bin Li ◽  
Yan-feng Qiao
Keyword(s):  
Topology Optimization ◽  
New Method ◽  
Truss Topology Optimization ◽  
Ground Structure ◽  
Truss Topology

Large-Scale Topology Optimization Using Parameterized Boolean Networks

2014 ◽  
Author(s):  
Ashish Khetan ◽  
James T. Allison
Keyword(s):  
Genetic Algorithm ◽  
Topology Optimization ◽  
Large Scale ◽  
Random Network ◽  
Boolean Networks ◽  
Size Optimization ◽  
Binary Representation ◽  
Ground Structure ◽  
Network Representation ◽  
Truss Topology

A novel parameterization concept for structural truss topology optimization is presented in this article that enables the use of evolutionary algorithms in design of large-scale structures. The representational power of Boolean networks is used here to parameterize truss topology. A genetic algorithm then operates on parameters that govern the generation of truss topologies using this random network instead of operating directly on design variables. A genetic algorithm implementation is also presented that is congruent with the local rule application of the random network. The primary advantage of using a Boolean random network representation is that a relatively large number of ground structure nodes can be used, enabling successful exploration of a large-scale design space. In the classical binary representation of ground structures, the number of optimization variables increases quadratically with the number of nodes, restricting the maximum number of nodes that can be considered using a ground structure approach. The Boolean random network representation proposed here allows for the exploration of the entire topology space in a systematic way using only a linear number of variables. The number of nodes in the design domain, therefore, can be increased significantly. Truss member geometry and size optimization is performed here in a nested manner where an inner loop size optimization problem is solved for every candidate topology using sequential linear programming with move-limits. The Boolean random network and nested inner-loop optimization allows for the concurrent optimization of truss topology, geometry, and size. The effectiveness of this method is demonstrated using a planar truss design optimization benchmark problem.

Optimization design of titanium alloy connecting rod based on structural topology optimization

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Bin Zheng ◽  
Yi Cai ◽  
Kelun Tang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Topology Optimization ◽  
Optimization Design ◽  
Equivalent Stress ◽  
Connecting Rod ◽  
Element Analysis ◽  
Content Type ◽  
The Finite Element Analysis ◽  
Maximum Equivalent Stress

Purpose The purpose of this paper is to realize the lightweight of connecting rod and meet the requirements of low energy consumption and vibration. Based on the structural design of the original connecting rod, the finite element analysis was conducted to reduce the weight and increase the natural frequencies, so as to reduce materials consumption and improve the energy efficiency of internal combustion engine. Design/methodology/approach The finite element analysis, structural optimization design and topology optimization of the connecting rod are applied. Efficient hybrid method is deployed: static and modal analysis; and structure re-design of the connecting rod based on topology optimization. Findings After the optimization of the connecting rod, the weight is reduced from 1.7907 to 1.4875 kg, with a reduction of 16.93%. The maximum equivalent stress of the optimized connecting rod is 183.97 MPa and that of the original structure is 217.18 MPa, with the reduction of 15.62%. The first, second and third natural frequencies of the optimized connecting rod are increased by 8.89%, 8.85% and 11.09%, respectively. Through the finite element analysis and based on the lightweight, the maximum equivalent stress is reduced and the low-order natural frequency is increased. Originality/value This paper presents an optimization method on the connecting rod structure. Based on the statics and modal analysis of the connecting rod and combined with the topology optimization, the size of the connecting rod is improved, and the static and dynamic characteristics of the optimized connecting rod are improved.

Lifting Technique of Composite Bucket Foundation for Offshore Wind Turbines

2020 ◽  
Author(s):  
Hongyan Ding ◽  
Zuntao Feng ◽  
Puyang Zhang ◽  
Conghuan Le
Keyword(s):  
Finite Element ◽  
Prestressed Concrete ◽  
Large Scale ◽  
Element Model ◽  
Offshore Wind ◽  
Force Transmission ◽  
Element Analysis ◽  
Bucket Foundation ◽  
Transition Section ◽  
Section Structure

Abstract The onshore pre-fabrication technology for composite bucket foundations takes “prefabrication-assembly-lifting” as the core concept. The practice of pre-fabrication of upper and lower structures is prefabricated respectively. In the research of hoisting engineering technology, combined with the structural form and construction requirements of composite bucket foundation, the assembly scheme of the upper prestressed concrete transition section and the lower steel bucket and the hoisting scheme of integral foundation with compartments were designed. The finite element model in the lifting process of composite bucket foundation was established by the large-scale general finite element analysis software ABAQUS. For the optimization analysis of the lifting point arrangement during hoisting process, the number, position and arrangement form of lifting points are simulated and analyzed. The results show that the maximum value of the principal stress of the concrete transition section structure appears in the assembly stage with the lower steel bucket, and the structure checking calculation should be carried out as the most unfavorable lifting condition in construction; the peak point of structural stress is at the junction of girder and secondary beams and inner ring beams of concrete roof, which belongs to the weak position of force transmission. In construction, it should be paid attention to as the key part of monitoring to ensure composite bucket foundation is under reasonable stress and the stability in the lifting process. The research results can provide guidance and reference for the future batch production and standardization production construction for composite bucket foundations.

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