Topology-Boundary Optimization of Coupled Structural-Acoustic Systems

Author(s):  
Lei Shu ◽  
Zhengdong Ma ◽  
Zongde Fang

A new topology optimization technique is presented in this paper for optimal design of coupled structural-acoustic system with a current focus on interior noise reduction of automotive vehicles. The new topology optimization technique is based on an earlier published work on the analysis and sensitivity analysis of the coupled structural-acoustic system [1–2]. It is extended in this paper to consider the optimum material distribution in the structural domain as well as the optimum boundary shape between the structural and acoustic domains for the purpose of interior noise reduction. Firstly, a fixed boundary problem was considered with a focus on the material distribution in the structural domain to achieve the desired acoustic response inside the acoustic domain. The general formulation developed accounts for the full coupling effect of the structural vibration and acoustic pressure and can consider multiple (structural and acoustic) inputs and outputs over a predefined frequency domain. Secondly, optimization of the boundary shape between the structural domain and acoustic domain is considered with a focus on modifying acoustic resonant modes as well as the interaction between the structure and acoustic field. Finally, optimal material distribution and boundary determination are simultaneously considered to obtain a truly optimum structural-acoustic system for the desired performance requirements of the coupled system. Examples will be given to demonstrate the feasibility and effectiveness of the new topology optimization technique for various applications.

2005 ◽  
Vol 73 (4) ◽  
pp. 565-573 ◽  
Author(s):  
Zheng-Dong Ma ◽  
Noboru Kikuchi ◽  
Christophe Pierre ◽  
Basavaraju Raju

A multidomain topology optimization technique (MDTO) is developed, which extends the standard topology optimization method to the realm of more realistic engineering design problems. The new technique enables the effective design of a complex engineering structure by allowing the designer to control the material distribution among the subdomains during the optimal design process, to use multiple materials or composite materials in the various subdomains of the structure, and to follow a desired pattern or tendency for the material distribution. A new algorithm of Sequential Approximate Optimization (SAO) is proposed for the multidomain topology optimization, which is an enhancement and a generalization of previous SAO algorithms (including Optimality Criteria and Convex Linearization methods, etc.). An advanced substructuring method using quasi-static modes is also introduced to condense the nodal variables associated with the multidomain topology optimization problem, especially for the nondesign subdomains. The effectiveness of the new MDTO approach is demonstrated for various design problems, including one of “structure-fixture simultaneous design,” one of “functionally graded material design,” and one of “crush energy management.” These case studies demonstrate the potential significance of the new capability developed for a wide range of engineering design problems.


Author(s):  
Zheng-Dong Ma ◽  
Noboru Kikuchi ◽  
Christophe Pierre ◽  
Basavaraju Raju

Topology optimization of a structure is generally considered as a problem of optimum material distribution (OMD) within a given structural domain, subject to a given amount of material and to boundary conditions and loading conditions applied to the structure. The effective design of a complex engineering structure, however, may require controllability over how the material should be distributed among the various subdomains of the structure, as well as even the use of different materials for the different subdomains. A multi-domain topology optimization technique is therefore proposed in this paper, which is based upon the homogenization method, and which employs a generalized Sequential Approximation Optimization (GSAO) algorithm. This algorithm enhances the capabilities of current topology optimization methods by using advanced updating rules and providing additional flexibility in the optimization process, thus resulting in improved convergence and higher computational efficiency. A Component Mode Synthesis method is also employed, which can significantly reduce the number of degrees of freedom associated with the subdomains whose designs are fixed at the current stage. Several example design problems are considered, including a “structure-fixture simultaneous design” problem, a “functionally graded material design” problem, a “crush energy management” problem, and a “truck frame design” problem that illustrates how the technique developed can be applied to real vehicle substructure design problems.


2006 ◽  
Vol 326-328 ◽  
pp. 1217-1220
Author(s):  
S.H. Choi ◽  
J.Y. Park ◽  
I.S. Shin ◽  
Seok Young Han

Topology optimization of the inner reinforcement for a vehicle’s hood has been performed by evolutionary structural optimization (ESO) method. The purpose of this study is to obtain optimal topology of the inner reinforcement for a vehicle’s hood considering static stiffness and natural frequency simultaneously. To do this, the multiobjective design optimization technique was implemented. From several combinations of weighting factors, a Pareto-optimal solution was obtained. Optimal topologies were obtained by the ESO method, i.e., by eliminating the elements having the lowest efficiency from the structural domain. As the weighting factor of the elastic strain efficiency goes from 1 to zero, it is found that the optimal topologies transmits from the optimal topology of static stiffness problem to that of natural frequency problem. Therefore, it was concluded that ESO method is effectively applied to topology optimization of the inner reinforcement of a vehicle’s hood.


Designs ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 19
Author(s):  
Andreas K. Lianos ◽  
Harry Bikas ◽  
Panagiotis Stavropoulos

The design methodologies and part shape algorithms for additive manufacturing (AM) are rapidly growing fields, proven to be of critical importance for the uptake of additive manufacturing of parts with enhanced performance in all major industrial sectors. The current trend for part design is a computationally driven approach where the parts are algorithmically morphed to meet the functional requirements with optimized performance in terms of material distribution. However, the manufacturability restrictions of AM processes are not considered at the primary design phases but at a later post-morphed stage of the part’s design. This paper proposes an AM design method to ensure: (1) optimized material distribution based on the load case and (2) the part’s manufacturability. The buildability restrictions from the direct energy deposition (DED) AM technology were used as input to the AM shaping algorithm to grant high AM manufacturability. The first step of this work was to define the term of AM manufacturability, its effect on AM production, and to propose a framework to estimate the quantified value of AM manufacturability for the given part design. Moreover, an AM design method is proposed, based on the developed internal stresses of the build volume for the load case. Stress tensors are used for the determination of the build orientation and as input for the part morphing. A top-down mesoscale geometric optimization is used to realize the AM part design. The DED Design for Additive Manufacturing (DfAM) rules are used to delimitate the morphing of the part, representing at the same time the freeform mindset of the AM technology. The morphed shape of the part is optimized in terms of topology and AM manufacturability. The topology optimization and AM manufacturability indicator (TMI) is introduced to screen the percentage of design elements that serve topology optimization and the ones that serve AM manufacturability. In the end, a case study for proof of concept is realized.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Aayush Bhat ◽  
Vyom Gupta ◽  
Savitoj Singh Aulakh ◽  
Renold S. Elsen

Purpose The purpose of this paper is to implement the generative design as an optimization technique to achieve a reasonable trade-off between weight and reliability for the control arm plate of a double-wishbone suspension assembly of a Formula Student race car. Design/methodology/approach The generative design methodology is applied to develop a low-weight design alternative to a standard control arm plate design. A static stress simulation and a fatigue life study are developed to assess the response of the plate against the loading criteria and to ensure that the plate sustains the theoretically determined number of loading cycles. Findings The approach implemented provides a justifiable outcome for a weight-factor of safety trade-off. In addition to optimal material distribution, the generative design methodology provides several design outcomes, for different materials and fabrication techniques. This enables the selection of the best possible outcome for several structural requirements. Research limitations/implications This technique can be used for applications with pre-defined constraints, such as packaging and loading, usually observed in load-bearing components developed in the automotive and aerospace sectors of the manufacturing industry. Practical implications Using this technique can provide an alternative design solution to long periods spent in the design phase, because of its ability to generate several possible outcomes in just a fraction of time. Originality/value The proposed research provides a means of developing optimized designs and provides techniques in which the design developed and chosen can be structurally analyzed.


Sign in / Sign up

Export Citation Format

Share Document