An Ants-Search Based Method for Optimum Synthesis of Compliant Mechanisms

2016 ◽  
Author(s):  
Nadim Diab ◽  
Ahmad Smaili
Keyword(s):  
Swarm Intelligence ◽  
Smart Materials ◽  
Compliant Mechanisms ◽  
Optimization Problems ◽  
Compliant Mechanism ◽  
Topology Design ◽  
Micro Electro Mechanical Systems ◽  
Amplification Ratio ◽  
The Past ◽  
Optimum Synthesis

Compliant mechanisms are widely used in the industry and have gained more popularity in the past few decades with the advancements in smart materials and micro-electro mechanical systems (MEMS). Compliant mechanisms offer huge advantages over the classical rigid linkages due to their flexible behavior. Such flexible mechanisms reduce production time and cost especially that they eliminate the need of joints that can get pretty hectic especially at micro level manufacturing and assembly. By avoiding multi-joints in the design and their consequent clearances, a compliant mechanism can offer higher precision over its rigid counterpart. However, these advantages come with a price; compliant mechanisms are more challenging in terms of design and analysis. Many compliant mechanisms are designed to undergo relatively large deflections which in turn impose geometric nonlinearities. In the past, many compliant designs were based on intuition, experience, and trial and error. Later on, many theories developed to assist in designing and analyzing compliant mechanisms before proceeding with the manufacturing phase. This paper covers topology optimization of compliant structures using beam elements. The swarm intelligence technique known as Ant Search (AS) is used to find the optimum design that satisfies the required mechanism performance. A case study that involves the topology design of a miniature compliant displacement amplifier is presented and results are compared with the finite element solver ANSYS. The optimized topology mechanism produced a much larger amplification ratio as compared to that presented in literature. Results produced show the high potential of swarm intelligence and AS in particular at solving multi-disciplinary optimization problems that should not be limited to designs that involve physical paths.

Modified IWO algorithm for topological optimum synthesis of the displacement amplifying compliant mechanism

2021 ◽  
pp. 095440892110110
Author(s):  
SM Varedi-Koulaei ◽  
MR MohammadZadeh
Keyword(s):  
Topology Optimization ◽  
Optimal Design ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Invasive Weed Optimization ◽  
Invasive Weed ◽  
High Stiffness ◽  
Optimum Synthesis ◽  
Transmitted Force ◽  
Random Step

The conventional mechanisms transmitted force and displacement through rigid members (high stiffness) and traditional joints (with high softness), where recently, researchers have come up with new systems called compliant mechanisms that transfer power and mobility through the deformation of their flexible members. One of the most frequently used approaches for designing compliant mechanisms is topology optimization. Extracting the optimal design of a displacement amplifying compliant mechanism using the modified Invasive Weed Optimization (MIWO) method is the current study's main novelty. The studied mechanism is a compliant micro-mechanism that can be used as a micrometric displacement amplifier. The goal of this synthesis is to maximize the output-to-input displacement ratio. In this research, a new random step is added to the Invasive Weed Optimization (IWO) method; the new seeds can be spread farther from their parents, which can be improved the algorithm's abilities. The results show that the use of the modified IWO algorithm for this problem has led to a significant improvement over the results from similar articles.

Hinged Beam Elements for the Topology Design of Compliant Mechanisms Using the Ground Structure Approach

2006 ◽  
Author(s):  
Deepak S. Ramrkahyani ◽  
Mary I. Frecker ◽  
George A. Lesieutre
Keyword(s):  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Topology Design ◽  
Ground Structure ◽  
Topology Optimization Problem ◽  
Beam Elements ◽  
New Type ◽  
Beam Type ◽  
Compliant Mechanism Design ◽  
Ground Structure Approach

The design obtained from a topology optimization problem can largely depend on the type of the ground structure used. A new type of ground structure containing hinged beam elements is described in this paper that reduces the dependence of the optimal design on the ground structure. Apart from the beam and truss elements that have traditionally been used, two new types of elements are introduced: 1) a beam with a hinge on one end and a solid connection on the other end, 2) beam element with hinges on both ends. These elements are particularly useful when applied to a compliant mechanism design using a truss/beam type ground structure. A couple of compliant mechanism problems are solved to demonstrate the effectiveness of these elements.

Distributed Shape Optimization of Compliant Mechanisms Using Intrinsic Functions

2007 ◽  
Author(s):  
Chao-Chieh Lan ◽  
Yung-Jen Cheng
Keyword(s):  
Stress Concentration ◽  
Shooting Method ◽  
Abrupt Change ◽  
Compliant Mechanisms ◽  
Optimization Problems ◽  
Compliant Mechanism ◽  
Design Method ◽  
Geometry Optimization ◽  
Systematic Design ◽  
Body Type

A compliant mechanism transmits motion and force by deformation of its flexible members. It has no relative moving parts and thus involves no wear, lubrication, noise, and backlash. Compliant mechanisms aims to maximize flexibility while maintaining sufficient stiffness so that satisfactory output motion can be achieved. When designing compliant mechanisms, the resulting shapes sometimes lead to rigid-body type linkages where compliance and rotation is lumped at a few flexural pivots. These flexural pivots are prone to stress concentration and thus limit compliant mechanisms to applications that only require small-deflected motion. To overcome this problem, a systematic design method is presented to synthesize the shape of a compliant mechanism so that compliance is distributed more uniformly over the mechanism. With a selected topology and load conditions, this method characterizes the free geometric shape of a compliant segment by its rotation and thickness functions. These two are referred as intrinsic functions and they describe the shape continuously within the segment so there is no abrupt change in geometry. Optimization problems can be conveniently formulated with cusps and intersecting loops naturally circumvented. To facilitate the optimization process, a numerical algorithm based on the generalized shooting method will be presented to solve for the deflected shape. Illustrative examples will demonstrate that through the proposed design method, compliant mechanisms with distributed compliance will lessen stress concentration so they can be more robust and have larger deflected range. It is expected that the method can be applied to design compliant mechanisms that have a wide variety of applications from precision instruments to biomedical devices.

scholarly journals Design of Large-Displacement Compliant Mechanisms by Topology Optimization Incorporating Modified Additive Hyperelasticity Technique

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Liying Liu ◽  
Jian Xing ◽  
Qingwei Yang ◽  
Yangjun Luo
Keyword(s):  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Previous Method ◽  
Large Displacement ◽  
Topology Design ◽  
Optimization Process ◽  
Response Analysis ◽  
Modified Technique ◽  
Element Analysis ◽  
Output Displacement

This paper is focused on the topology design of compliant mechanisms undergoing large displacement (over 20% of the structural dimension). Based on the artificial spring model and the geometrically nonlinear finite element analysis, the optimization problem is formulated so as to maximize the output displacement under a given material volume constraint. A modified additive hyperelasticity technique is proposed to circumvent numerical instabilities that occurred in the low-density or intermediate-density elements during the optimization process. Compared to the previous method, the modified technique is very effective and can provide more accurate response analysis for the large-displacement compliant mechanism. The whole optimization process is carried out by the gradient-based mathematical programming method. Numerical examples of a force-inverting mechanism and a microgripping mechanism are presented. The obtained optimal solutions verify the applicability of the proposed numerical techniques and show the necessity of considering large displacement in the design problem.

Application of the Flexible Link Model (FLM) and Quantum Computing-Based Algorithm for the Optimum Synthesis of Partially Compliant Mechanisms

2012 ◽  
Author(s):  
Ahmad Smaili ◽  
Mazen Hassanieh ◽  
Nadim Diab
Keyword(s):  
Quantum Computing ◽  
Evolutionary Algorithm ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Flexible Link ◽  
Solution Vector ◽  
Optimum Synthesis ◽  
Design Variables ◽  
Link Model

The purpose of this paper is to integrate the concept of the flexible link model (FLM) with a modified real coded quantum inspired evolutionary algorithm (MRQIEA) for the optimum synthesis of partially compliant mechanisms. The purpose is to synthesize the compliant and rigid members of a partially compliant mechanism in a single optimization run. The compliant member parameters are defined by the FLM which facilitates the integration of the design variables associated with compliant members and rigid links in one solution vector. Four examples are presented to demonstrate the approach.

Using Compliant Mechanisms to Improve Manufacturability in MEMS

2002 ◽  
Author(s):  
Deanne Clements Kemeny ◽  
Larry L. Howell ◽  
Spencer P. Magleby
Keyword(s):  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Layered Manufacturing ◽  
Manufacturing Processes ◽  
Micro Electro Mechanical Systems ◽  
Critical Areas ◽  
Manufacturing Methods ◽  
Electrical Components ◽  
Design Challenges ◽  
Related Design

Micro-electro-mechanical systems (MEMS) consist of micro mechanisms integrated with electrical components. MEMS are often fabricated using a layered manufacturing approach with polysilicon. Because of certain challenges and constraints inherent in the manufacturing methods for MEMS, compliant mechanism technology is beneficial in designing these micro devices. This paper examines the interaction of compliant mechanisms (CMs) and MEMS in three areas: (1) the characteristics of CMs that make them attractive to use in MEMS, (2) the challenges presented to the use of CMs due to the manufacturing processes inherent in MEMS, and (3) performance-related design challenges with CMs and MEMS. These are critical areas of design when considering manufacturability in MEMS.

scholarly journals Innovative concept of compliant mechanisms made by additive manufacturing

2019 ◽  
Vol 304 ◽  
pp. 07002
Author(s):  
Lionel Kiener ◽  
Hervé Saudan ◽  
Florent Cosandier ◽  
Gérald Perruchoud ◽  
Peter Spanoudakis
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
European Space Agency ◽  
Harsh Environment ◽  
Use Case ◽  
The Past ◽  
Space Agency ◽  
Innovative Concept

The complete redesign for Additive Manufacturing of compliant mechanism structures enables CSEM to develop innovative concepts to drastically reduce the need of machining and assembly after additive manufacturing. Support structures under flexure blades are thus minimised and the overall process becomes more streamlined. Moreover, this concept allows us to easily design and produce monolithic cross flexure pivots with interlocked flexible blades. Based on this concept, CSEM is now developing new architectures of Compliant Mechanisms based on Additive Manufacturing (COMAM) for the European Space Agency (ESA) in the frame of a GSTP research project. The past and current work of design, 3D printing and testing on several compliant mechanisms are presented. These demonstrators will be used as use-case for future high-precision and harsh environment applications such as cryogenic and space.

Distributed Shape Optimization of Compliant Mechanisms Using Intrinsic Functions

2008 ◽  
Vol 130 (7) ◽  
Author(s):  
Chao-Chieh Lan ◽  
Yung-Jen Cheng
Keyword(s):  
Stress Concentration ◽  
Shooting Method ◽  
Abrupt Change ◽  
Compliant Mechanisms ◽  
Optimization Problems ◽  
Compliant Mechanism ◽  
Design Method ◽  
Geometry Optimization ◽  
Systematic Design ◽  
Body Type

A compliant mechanism transmits motion and force by deformation of its flexible members. It has no relative moving parts and thus involves no wear, lubrication, noise, or backlash. Compliant mechanisms aim to maximize flexibility while maintaining sufficient stiffness so that satisfactory output motion may be achieved. When designing compliant mechanisms, the resulting shapes sometimes lead to rigid-body type linkages where compliance and rotation is lumped at a few flexural pivots. These flexural pivots are prone to stress concentration and thus limit compliant mechanisms to applications that only require small-deflected motion. To overcome this problem, a systematic design method is presented to synthesize the shape of a compliant mechanism so that compliance is distributed more uniformly over the mechanism. With a selected topology and load conditions, this method characterizes the free geometric shape of a compliant segment by its rotation and thickness functions. These two are referred as intrinsic functions and they describe the shape continuously within the segment so there is no abrupt change in geometry. Optimization problems can be conveniently formulated with cusps and intersecting loops naturally circumvented. To facilitate the optimization process, a numerical algorithm based on the generalized shooting method will be presented to solve for the deflected shape. Illustrative examples will demonstrate that through the proposed design method, compliant mechanisms with distributed compliance will lessen stress concentration so they are more robust and have a larger deflected range. It is expected that the method can be applied to design compliant mechanisms for a wide variety of applications.

scholarly journals Multi-Task Optimization and Multi-Task Evolutionary Computation in the Past Five Years: A Brief Review

Mathematics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 864
Author(s):  
Qingzheng Xu ◽  
Na Wang ◽  
Lei Wang ◽  
Wei Li ◽  
Qian Sun
Keyword(s):  
Evolutionary Computation ◽  
Explicit Knowledge ◽  
Optimization Problems ◽  
Effective Means ◽  
Typical Application ◽  
The Past ◽  
Current State ◽  
Evolution Algorithms ◽  
Application Fields

Traditional evolution algorithms tend to start the search from scratch. However, real-world problems seldom exist in isolation and humans effectively manage and execute multiple tasks at the same time. Inspired by this concept, the paradigm of multi-task evolutionary computation (MTEC) has recently emerged as an effective means of facilitating implicit or explicit knowledge transfer across optimization tasks, thereby potentially accelerating convergence and improving the quality of solutions for multi-task optimization problems. An increasing number of works have thus been proposed since 2016. The authors collect the abundant specialized literature related to this novel optimization paradigm that was published in the past five years. The quantity of papers, the nationality of authors, and the important professional publications are analyzed by a statistical method. As a survey on state-of-the-art of research on this topic, this review article covers basic concepts, theoretical foundation, basic implementation approaches of MTEC, related extension issues of MTEC, and typical application fields in science and engineering. In particular, several approaches of chromosome encoding and decoding, intro-population reproduction, inter-population reproduction, and evaluation and selection are reviewed when developing an effective MTEC algorithm. A number of open challenges to date, along with promising directions that can be undertaken to help move it forward in the future, are also discussed according to the current state. The principal purpose is to provide a comprehensive review and examination of MTEC for researchers in this community, as well as promote more practitioners working in the related fields to be involved in this fascinating territory.

scholarly journals Magnetoactive elastomers for magnetically tunable vibrating sensor systems

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Tatiana I. Becker ◽  
Yuriy L. Raikher ◽  
Oleg V. Stolbov ◽  
Valter Böhm ◽  
Klaus Zimmermann
Keyword(s):  
Magnetic Field ◽  
Steady State ◽  
Smart Materials ◽  
Excitation Frequency ◽  
Experimental Studies ◽  
Uniform Field ◽  
Sensor Systems ◽  
Ongoing Research ◽  
Amplification Ratio ◽  
Field Distortion

Abstract Magnetoactive elastomers (MAEs) are a special type of smart materials consisting of an elastic matrix with embedded microsized particles that are made of ferromagnetic materials with high or low coercivity. Due to their composition, such elastomers possess unique magnetic field-dependent material properties. The present paper compiles the results of investigations on MAEs towards an approach of their potential application as vibrating sensor elements with adaptable sensitivity. Starting with the model-based and experimental studies of the free vibrational behavior displayed by cantilevers made of MAEs, it is shown that the first bending eigenfrequency of the cantilevers depends strongly on the strength of an applied uniform magnetic field. The investigations of the forced vibration response of MAE beams subjected to in-plane kinematic excitation confirm the possibility of active magnetic control of the amplitude-frequency characteristics. With change of the uniform field strength, the MAE beam reveals different steady-state responses for the same excitation, and the resonance may occur at various ranges of the excitation frequency. Nonlinear dependencies of the amplification ratio on the excitation frequency are obtained for different magnitudes of the applied field. Furthermore, it is shown that the steady-state vibrations of MAE beams can be detected based on the magnetic field distortion. The field difference, which is measured simultaneously on the sides of a vibrating MAE beam, provides a signal with the same frequency as the excitation and an amplitude proportional to the amplitude of resulting vibrations. The presented prototype of the MAE-based vibrating unit with the field-controlled “configuration” can be implemented for realization of acceleration sensor systems with adaptable sensitivity. The ongoing research on MAEs is oriented to the use of other geometrical forms along with beams, e.g. two-dimensional structures such as membranes.

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