Design Synthesis of Path Generating Compliant Mechanisms by Evolutionary Optimization of Topology and Shape

2002 ◽  
Vol 124 (3) ◽  
pp. 492-500 ◽  
Author(s):  
Kang Tai ◽  
Guang Yu Cui ◽  
Tapabrata Ray
Keyword(s):  
Evolutionary Algorithm ◽  
Compliant Mechanisms ◽  
Design Procedure ◽  
Evolutionary Process ◽  
Shape Design ◽  
Discrete Optimization Problem ◽  
Design Synthesis ◽  
Computationally Intensive ◽  
Representation Scheme ◽  
Shape Characteristics

This work demonstrates the successful synthesis of path generating compliant mechanisms by the process of topology and shape design optimization. As geometric topology variation of continuum structures is difficult to treat and analysis of the displacement path or trajectory of such structures is computationally intensive, a highly effective and efficient optimal design procedure is needed. This paper describes the use of a recently developed morphological geometric representation scheme coupled with an evolutionary algorithm to synthesize the mechanism. The scheme uses arrangements of skeleton and “flesh” to define structural geometry, which facilitates transmission of topological/shape characteristics across generations in the evolutionary process and will not render any geometrically invalid designs. The evolutionary algorithm solves the problem as a discrete optimization problem, with a proficient constraint handling capability.

Design Synthesis of Path Generating Compliant Mechanisms by Evolutionary Optimization of Topology and Shape

2000 ◽  
Author(s):  
Kang Tai ◽  
Guang Yu Cui ◽  
Tapabrata Ray
Keyword(s):  
Evolutionary Algorithm ◽  
Compliant Mechanisms ◽  
Evolutionary Process ◽  
Shape Design ◽  
Discrete Optimization Problem ◽  
Design Synthesis ◽  
Optimization Methodology ◽  
Computationally Intensive ◽  
Representation Scheme ◽  
Shape Characteristics

Abstract This work demonstrates the successful synthesis of path generating compliant mechanisms by the process of topology and shape design optimization. As geometric topology variation of continuum structures is difficult to treat and analysis of the displacement path or trajectory of such structures is computationally intensive, a highly effective and efficient optimization methodology is needed. This paper describes the use of a recently developed morphological geometric representation scheme coupled with an evolutionary algorithm to synthesize the mechanism. The scheme uses arrangements of skeleton and ‘flesh’ to define structural geometry, which facilitates transmission of topological/shape characteristics across generations in the evolutionary process and will not render any geometrically invalid designs. The evolutionary algorithm solves the problem as a discrete optimization problem, with a proficient constraint handling capability.

Design of Structures and Compliant Mechanisms by Evolutionary Optimization of Morphological Representations of Topology

1998 ◽  
Vol 122 (4) ◽  
pp. 560-566 ◽  
Author(s):  
K. Tai ◽  
T. H. Chee
Keyword(s):  
Optimization Problem ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Evolutionary Process ◽  
Discrete Optimization Problem ◽  
Structural Geometry ◽  
Design Synthesis ◽  
Continuum Structures ◽  
Representation Scheme ◽  
Shape Characteristics

This paper demonstrates the automatic design synthesis of continuum structures by the process of topology/shape optimization. The problem is solved as a discrete optimization problem using the genetic algorithm (GA). Past efforts using this approach have not been very effective due to the lack of an appropriate structural geometric representation which is highly essential to the success of the evolutionary processes of the GA. Based on the morphology of living creatures, a representation scheme has been developed using arrangements of skeleton and ‘flesh’ to define structural geometry. This scheme facilitates the transmission of topological and shape characteristics across generations in the evolutionary process, and will not render any structurally invalid designs. Good results are illustrated using this scheme to design a compliant mechanism and a cantilever beam. [S1050-0472(00)02104-8]

Estimating Optimized Stress Bounds in Early Stage Design of Compliant Mechanisms

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Sree Kalyan Patiballa ◽  
Girish Krishnan
Keyword(s):  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Early Stage ◽  
Functional Characterization ◽  
Stress Constraints ◽  
Design Synthesis ◽  
Stage Design ◽  
Computationally Intensive ◽  
Early Stage Design ◽  
Selection Of

Design synthesis of distributed compliant mechanisms is often a two-stage process involving (a) conceptual topology synthesis and a subsequent (b) refinement stage to meet strength and manufacturing specifications. The usefulness of a solution is ascertained only after the sequential completion of these two steps that are, in general, computationally intensive. This paper presents a strategy to rapidly estimate final operating stresses even before the actual refinement process. This strategy is based on the uniform stress distribution metric, and a functional characterization of the different members that constitute the compliant mechanism topology. Furthermore, this paper uses the underlying mechanics of stress bound estimation to propose two rule of thumb guidelines for insightful selection of topologies and systematically modifying them for an application. The selection of the best conceptual solution in the early stage design avoids refinement of topologies that inherently may not meet the stress constraints. This paper presents two examples that illustrate these guidelines through the selection and refinement of topologies for a planar compliant gripper application.

CADDAC: Multi-Client Collaborative Shape Design System with Server-based Geometry Kernel

2003 ◽  
Vol 3 (2) ◽  
pp. 170-173 ◽  
Author(s):  
Karthik Ramani, ◽  
Abhishek Agrawal, and ◽  
Mahendra Babu ◽  
Christoph Hoffmann
Keyword(s):  
Global Economy ◽  
Design System ◽  
Shape Design ◽  
Server Side ◽  
Collaborative Product Design ◽  
Flexible Architecture ◽  
Computationally Intensive ◽  
New Feature ◽  
Rendering Pipeline ◽  
Client Side

New and efficient paradigms for web-based collaborative product design in a global economy will be driven by increased outsourcing, increased competition, and pressures to reduce product development time. We have developed a three-tier (client-server-database) architecture based collaborative shape design system, Computer Aided Distributed Design and Collaboration (CADDAC). CADDAC has a centralized geometry kernel and constraint solver. The server-side provides support for solid modeling, constraint solving operations, data management, and synchronization of clients. The client-side performs real-time creation, modification, and deletion of geometry over the network. In order to keep the clients thin, many computationally intensive operations are performed at the server. Only the graphics rendering pipeline operations are performed at the client-side. A key contribution of this work is a flexible architecture that decouples Application Data (Model), Controllers, Viewers, and Collaboration. This decoupling allows new feature development to be modular and easy to develop and manage.

Load-Transmitter Constraint Sets: Part I—An Effective Tool for Visualizing Load Flow in Compliant Mechanisms and Structures

2010 ◽  
Author(s):  
Girish Krishnan ◽  
Charles Kim ◽  
Sridhar Kota
Keyword(s):  
Building Block ◽  
Deformation Behavior ◽  
Design Methodology ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Load Flow ◽  
Mathematical Framework ◽  
Design Synthesis ◽  
Fundamental Building Block ◽  
Block Based

Visualizing load flow aids in conceptual design synthesis of machine components. In this paper, we present a mathematical framework to visualize load flow in compliant mechanisms and structures. This framework uses the concept of transferred forces to quantify load flow from input to the output of a compliant mechanism. The key contribution of this paper is the identification a fundamental building block known as the Load-Transmitter Constraint (LTC) set, which enables load flow in a particular direction. The transferred force in each LTC set is shown to be independent of successive LTC sets that are attached to it. This enables a continuous visualization of load flow from the input to the output. Furthermore, we mathematically relate the load flow with the deformation behavior of the mechanism. We can thus explain the deformation behavior of a number of compliant mechanisms from literature by identifying its LTC sets to visualize load flow. This method can also be used to visualize load flow in optimal stiff structure topologies. The insight obtained from this visualization tool facilitates a systematic building block based design methodology for compliant mechanisms and structural topologies.

Toward an automated approach to the design of sheet metal components

2003 ◽  
Vol 17 (3) ◽  
pp. 187-204 ◽  
Author(s):  
ADITYA SOMAN ◽  
SWAPNIL PADHYE ◽  
MATTHEW I. CAMPBELL
Keyword(s):  
Sheet Metal ◽  
User Interaction ◽  
Computational Design ◽  
Design Synthesis ◽  
Manufacturing Operations ◽  
Grammar Rules ◽  
Computational Design Synthesis ◽  
Representation Scheme ◽  
Sheet Metal Component ◽  
Synthesis Approach

The design of sheet metal components is perhaps one of the more challenging concurrent activities for design and manufacturing engineers. To aid this design process, a method is developed to encapsulate the constraints of sheet metal that make designing such components a tedious and iterative procedure. This project involves the implementation and testing of a geometric representation scheme for building feasible sheet metal components through the use of 17 grammar rules that capture manufacturing operations like cutting and bending. The implemented system has benefits both as a user interaction tool and as the basis for a computational design synthesis approach for designing sheet metal components. An example of a constructed sheet metal component is shown along with the method for invoking the sheet metal grammar to create this component.

Incorporation of Preferences in an Evolutionary Algorithm Using an Outranking Relation

2011 ◽  
Vol 2 (1) ◽  
pp. 63-85 ◽  
Author(s):  
Eunice Oliveira ◽  
Carlos Henggeler Antunes ◽  
Álvaro Gomes
Keyword(s):  
Evolutionary Algorithm ◽  
Evolutionary Process ◽  
Computational Effort ◽  
Cognitive Effort ◽  
Point Of View ◽  
Electrical Networks ◽  
Technical Parameters ◽  
Outranking Relation ◽  
Electre Tri

The incorporation of preferences into Evolutionary Algorithms (EA) presents some relevant advantages, namely to deal with complex real-world problems. It enables focus on the search thus avoiding the computation of irrelevant solutions from the point of view of the practical exploitation of results (thus minimizing the computational effort), and it facilitates the integration of the DM’s expertise into the solution search process (thus minimizing the cognitive effort). These issues are particularly important whenever the number of conflicting objective functions and/or the number of non-dominated solutions in the population is large. In EvABOR (Evolutionary Algorithm Based on an Outranking Relation) approaches preferences are elicited from a decision maker (DM) with the aim of guiding the evolutionary process to the regions of the space more in accordance with the DM’s preferences. The preferences are captured and made operational by using the technical parameters of the ELECTRE TRI method. This approach is presented and analyzed using some illustrative results of a case study of electrical networks.

scholarly journals Solving the problem of optimal design for a two-stage reducer by using a modified evolutionary algorithm

2020 ◽  
Vol 317 ◽  
pp. 01004
Author(s):  
Oleksandr Ustynenko ◽  
Oleksiy Bondarenko ◽  
Volodymyr Serykov
Keyword(s):  
Optimal Design ◽  
Evolutionary Algorithm ◽  
Specific Problem ◽  
Functional Limitations ◽  
Evolutionary Process ◽  
Design Parameters ◽  
Initial Population ◽  
Objective Functions ◽  
Two Stage ◽  
Test Points

The work is devoted to solving the problem of selecting optimal geometric parameters of gears of a two-stage cylindrical reducer using a modified evolutionary algorithm (EA). The statement of the problem is considered, design parameters, objective functions, limitations on design parameters are determined. This allowed us to propose a modification of EA. To generate the initial test points, it was proposed to use the LP-τ sequence, this allowed us to reduce the initial population of test points and bring EA closer to a truly “random” process. The scheme of the proposed algorithm is considered, which gives an idea of the sequence of operations that are carried out with populations of test points at each stage of the evolutionary process. The solution of the specific problem of selecting optimal parameters for a serial reducer is given. The input data, numerical and functional limitations are determined, the objective functions are formed. The results of the solution are shown in several presentation formats: tabular and graphical, which allows to qualitatively interpret and analyze the results. Conclusions are made about testing the proposed algorithm for solving a specific problem of optimal design. Further ways of improving this methodology are proposed.

Efficient Development of Continuum/Compliant Planar Linkage Mechanisms

2019 ◽  
Author(s):  
Woo Rib Suh ◽  
J. Michael McCarthy ◽  
Edwin A. Peraza Hernandez
Keyword(s):  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Shape Parameters ◽  
Element Analysis ◽  
Initial Node ◽  
Synthesis Of Mechanisms ◽  
Efficient Alternative ◽  
Computationally Intensive ◽  
The Given ◽  
The Continuum

Abstract This paper presents a method to develop continuum/compliant mechanisms based on planar bar-node linkage precursors. The method takes as inputs the initial node positions and connectivity data of a given bar-node linkage and converts it into a continuum/compliant mechanism having the same targeted motion. The line bars of the given bar-node linkage are thickened into trapezoidal planar members and the nodes are thickened by introducing fillets at each intersection of bars. The thicknesses of the bars and the shape parameters of the fillets in the continuum/compliant linkage are optimized to obtain the same targeted motion of the given bar-node linkage while keeping stresses below a maximum allowable value. Each design generated during the optimization process is evaluated using finite element analysis. The present method allows for the synthesis of mechanisms having the following advantages over conventional bar-node linkages: 1) They do not require complex ball or pin joints; 2) they can be readily 3-D printed and size-scaled, and 3) they can be optimized to decrease stresses below a maximum allowable value. Furthermore, the method uses a relatively small number of optimization variables (thicknesses of the members, shape-parameters of the fillets), making it an efficient alternative to more complex and computationally intensive methods for synthesizing compliant mechanisms such as those incorporating topology optimization.

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