• 제목, 요약, 키워드: Topology Optimization

검색결과 578건 처리시간 0.032초

점탄성물질 위치 최적화를 위한 설계변수감소 위상최적설계 기법 (RDVM Topology Optimization for Optimal Damping Treatment)

  • 김선용
    • 한국소음진동공학회논문집
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    • v.27 no.1
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    • pp.72-79
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    • 2017
  • A full treatment of damping material is not an effective method because the damping effect is not significantly increased compared to that obtained by an effective partial damping treatment. Thus, a variety of methodologies has been considered in order to achieve an optimal damping treatment. One of the widely applied approaches is topology optimization. However, the high computational expenses can be an issue in topology optimization. A new efficient convergence criterion, reducible design variable method (RDVM), is applied to reduce computational expense in topology optimization. The idea of RDVM topology optimization is to adaptively reduce the number of design variables based on the history. The iteration repeats until the number of design variables becomes zero. The aim of this research is to adopt RDVM topology optimization into obtaining an optimal damping treatment. In order to demonstrate the effectiveness and efficiency of RDVM topology optimization, optimal damping layouts and computational expenses are compared between conventional and RDVM topology optimization.

Reliability-Based Topology Optimization for Different Engineering Applications

  • Kharmanda, G.;Lambert, S.;Kourdi, N.;Daboul, A.;Elhami, A.
    • International Journal of CAD/CAM
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    • v.7 no.1
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    • pp.61-69
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    • 2007
  • The objective of this work is to integrate reliability analysis into topology optimization problems. We introduce the reliability constraint in the topology optimization formulation, and the new model is called Reliability-Based Topology Optimization (RBTO). The application of the RBTO model gives a different topology relative to the classical topology optimization that should be deterministic. When comparing the structures resulting from the deterministic topology optimization and from the RBTO model, the RBTO model yields structures that are more reliable than the deterministic ones (for the same weight). Several applications show the importance of this integration.

신뢰성 해석을 이용한 차량 후드 보강재의 위상최적화 (Topology Optimization of the Inner Reinforcement of a Vehicle's Hood using Reliability Analysis)

  • 박재용;임민규;오영규;박재용;한석영
    • 한국생산제조학회지
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    • v.19 no.5
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    • pp.691-697
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    • 2010
  • Reliability-based topology optimization (RBTO) is to get an optimal topology satisfying uncertainties of design variables. In this study, reliability-based topology optimization method is applied to the inner reinforcement of vehicle's hood based on BESO. A multi-objective topology optimization technique was implemented to obtain optimal topology of the inner reinforcement of the hood. considering the static stiffness of bending and torsion as well as natural frequency. Performance measure approach (PMA), which has probabilistic constraints that are formulated in terms of the reliability index, is adopted to evaluate the probabilistic constraints. To evaluate the obtained optimal topology by RBTO, it is compared with that of DTO of the inner reinforcement of the hood. It is found that the more suitable topology is obtained through RBTO than DTO even though the final volume of RBTO is a little bit larger than that of DTO. From the result, multiobjective optimization technique based on the BESO can be applied very effectively in topology optimization for vehicle's hood reinforcement considering the static stiffness of bending and torsion as well as natural frequency.

SIMP를 이용한 구조물의 재료 위상 최적설계 Part II : 부분적인 솔리드 위상을 가지는 초기 설계영역 (Material Topology Optimization Design of Structures using SIMP Approach Part II : Initial Design Domain with Topology of Partial Solids)

  • 이동규;박성수;신수미
    • 한국전산구조공학회논문집
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    • v.20 no.1
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    • pp.19-28
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    • 2007
  • 이산화 된 구조물의 위상최적화 과정은 균일하게 분포된 재료 밀도의 위상으로 표현되는 초기 설계영역을 시발점으로 한다. 최적화 과정 동안 구조물의 위상은 고정된 설계영역 내에 주어진 최적화 문제를 만족시키는 방향으로 변화하면서, 최종적으로 최적 위상의 재료 밀도 분포를 생산한다. Eschenauer et al.에 의해 제안되었던 설계영역 안에 구멍을 도입하는 개념은 원래 경계면의 최적화 문제에 대해 설계변수의 유한적인 변화를 촉진시켜 최적화의 수렴성 개선을 도모하기 위함이었으나, 위상최적화의 관점에서는 초기 위상의 정의에 따라 다양한 최적 위상이 생산되는 것을 의미한다. 본 연구에서는 초기 설계영역 안에 국소적인 솔리드 상을 도입해 초기 위상에 변화를 주었을 때, 한정된 재료 하에 구조물에 배치 가능한 다양한 최적 위상을 산출할 수 있음을 검증하였다. 수치 예제로서 초기 설계영역 내에 다양한 치수를 가지는 국부적인 원형 솔리드의 고정된 개수를 투입하여 간단한 MBB-보의 위상최적 설계를 수행하였다.

최적조건법에 의한 위상 최적화 연구 (Topology Optimization using an Optimality Criteria Method)

  • 김병수;서명원
    • 한국자동차공학회논문집
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    • v.7 no.8
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    • pp.224-232
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    • 1999
  • Topology optimization has evolved into a very efficient concept design tool and has been incorporated into design engineering processes in many industrial sectors. In recent years, topology optimization has become the focus of structural design community and has been researched and applied widely both in academia and industry. There are mainly tow approaches for topology optimization of continuum structures ; homogenization and density methods. The homogenization method is to compute is to compute an optimal distribution of microstructures in a given design domain. The sizes of the micro-calvities are treated as design variables for the topology optimization problem. the density method is to compute an optimal distribution of an isotropic material, where the material densities are treated as design variables. In this paper, the density method is used to formulate the topology optimization problem. This optimization problem is solved by using an optimality criteria method. Several example problems are solved to show the usefulness of the present approach.

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주행시 궤도차량 바닥판의 위상최적설계에 관한 연구 (A Study on Topology Optimization of the Tracked Vehicle Bottom Plate under Traveling Loading)

  • 황영진;김종범;이석순;최창곤;손재흥
    • 대한기계학회:학술대회논문집
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    • pp.558-563
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    • 2003
  • The tracked vehicle travel on off rod and on rod. So the tracked vehicle need a sufficient stiffness and a lightweight. In this study we performed FEA for the track vehicle and performed topology optimization based on the results of FEA. The displacements of road wheel are used as displacement constraint for topology optimization. We performed topology optimization with the control of the frame size which is the results of topology optimization and suggested the shaped of the tracked vehicle bottom plate of topology optimization

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SIMP 기반 절점밀도법에 의한 3 차원 위상최적화 (3-D Topology Optimization by a Nodal Density Method Based on a SIMP Algorithm)

  • 김철;팡난
    • 대한기계학회:학술대회논문집
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    • pp.412-417
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    • 2008
  • In a traditional topology optimization method, material properties are usually distributed by finite element density and visualized by a gray level image. The distribution method based on element density is adequate for a great mass of 2-D topology optimization problems. However, when it is used for 3-D topology optimization, it is always difficult to obtain a smooth model representation, and easily appears a virtualconnect phenomenon especially in a low-density domain. The 3-D structural topology optimization method has been developed using the node density instead of the element density that is based on SIMP (solid isotropic microstructure with penalization) algorithm. A computer code based on Matlab was written to validate the proposed method. When it was compared to the element density as design variable, this method could get a more uniform density distribution. To show the usefulness of this method, several typical examples of structure topology optimization are presented.

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Topology optimization for thin plate on elastic foundations by using multi-material

  • Banh, Thien Thanh;Shin, Soomi;Lee, Dongkyu
    • Steel and Composite Structures
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    • v.27 no.2
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    • pp.177-184
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    • 2018
  • This study contributes to evaluate multiphase topology optimization design of plate-like structures on elastic foundations by using classic plate theory. Multi-material optimal topology and shape are produced as an alternative to provide reasonable material assignments based on stress distributions. Multi-material topology optimization problem is solved through an alternative active-phase algorithm with Gauss-Seidel version as an optimization model of optimality criteria. Stiffness and adjoint sensitivity formulations linked to thin plate potential strain energy are derived in terms of multiphase design variables and Winkler-Pasternak parameters considering elastic foundation to apply to the current topology optimization. Numerical examples verify efficiency and diversity of the present topology optimization method of elastic thin plates depending on multiple materials and Winkler-Pasternak parameters with the same amount of volume fraction and total structural volume.

균질화법을 이용한 수직형 롤러 분쇄기용 테이블 라이너의 위상최적설계에 관한 연구 (A Study on Topology Optimization of Table Liner for Vertical Roller Mill using Homogenization Method)

  • 이동우;홍순혁;조석수;이선봉;주원식
    • 한국정밀공학회지
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    • v.20 no.6
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    • pp.113-122
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    • 2003
  • Topology optimization is begun with layout optimization that is attributed to Rozvany and Prager of the 1960's. They claimed that structure was transformed into truss connecting all the nodes of finite element and optimized by control of its sectional modulus. But, this method is partial topology optimization. General layout optimal design appliable to continum structure was proposed by Bendsoe and Kikuchi in 1988. Topology optimization expresses material stiffness of structure into function of arbitrary variable. If this variable is 1, material exists but if this variable is 0, material doesn't exist. Therefore, topology optimization searches the distribution function of material stiffness for structure. There are a few researchs for simple engineering problem such as topology optimization of square plane structure or truss structure. So, This study applied to topology optimization of table liner for vertical roller mill that is the largest scale in the world. After table liner decreased by 20% of original weight, the structure analysis for first optimized model was performed.

등가정하중을 사용한 선형 동적반응 위상최적설계 기초연구 (Preliminary Study on Linear Dynamic Response Topology Optimization Using Equivalent Static Loads)

  • 장환학;이현아;박경진
    • 대한기계학회논문집A
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    • v.33 no.12
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    • pp.1401-1409
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    • 2009
  • All the forces in the real world act dynamically on structures. Design and analysis should be performed based on the dynamic loads for the safety of structures. Dynamic (transient or vibrational) responses have many peaks in the time domain. Topology optimization, which gives an excellent conceptual design, mainly has been performed with static loads. In topology optimization, the number of design variables is quite large and considering the peaks is fairly costly. Topology optimization in the frequency domain has been performed to consider the dynamic effects; however, it is not sufficient to fully include the dynamic characteristics. In this research, linear dynamic response topology optimization is performed in the time domain. First, the necessity of topology optimization to directly consider the dynamic loads is verified by identifying the relationship between the natural frequency of a structure and the excitation frequency. When the natural frequency of a structure is low, the dynamic characteristics (inertia effect) should be considered. The equivalent static loads (ESLs) method is proposed for linear dynamic response topology optimization. ESLs are made to generate the same response field as that from dynamic loads at each time step of dynamic response analysis. The method was originally developed for size and shape optimizations. The original method is expanded to topology optimization under dynamic loads. At each time step of dynamic analysis, ESLs are calculated and ESLs are used as the external loads in static response topology optimization. The results of topology optimization are used to update the design variables (density of finite elements) and the updated design variables are used in dynamic analysis in a cyclic manner until the convergence criteria are satisfied. The updating rules and convergence criteria in the ESLs method are newly proposed for linear dynamic response topology optimization. The proposed updating rules are the artificial material method and the element elimination method. The artificial material method updates the material property for dynamic analysis at the next cycle using the results of topology optimization. The element elimination method is proposed to remove the element which has low density when static topology optimization is finished. These proposed methods are applied to some examples. The results are discussed in comparison with conventional linear static response topology optimization.