A Compliance Number Concept for Compliant Mechanisms, and Type Synthesis

1987 ◽  
Vol 109 (3) ◽  
pp. 348-355 ◽  
Author(s):  
I. Her ◽  
A. Midha
Keyword(s):  
Rigid Body ◽  
Degrees Of Freedom ◽  
Compliant Mechanisms ◽  
Type Synthesis ◽  
Number Concept ◽  
Fundamental Level ◽  
The Past ◽  
Convenient Approach ◽  
Kinematic Properties

While much has been contributed to techniques for enumerating and identifying rigid-body mechanisms in the past decades, proportionally little has been accomplished in this regard in compliant mechanisms design. This paper deals primarily with identification and discussion of important kinematic properties of compliant mechanisms. To facilitate these appropriate terminology is developed at the very fundamental level. The conventional degrees-of-freedom concept for a rigid-body chain is briefly reviewed. It is then used to help define a compliance number (or degrees-of-compliance) concept for characterizing compliant mechanisms. Finally, a systematic and convenient approach is presented, enabling the type synthesis of this class of mechanisms.

Type Synthesis of Compliant Mechanisms Employing a Simplified Approach to Segment Type

1994 ◽  
Author(s):  
Morgan D. Murphy ◽  
Ashok Midha ◽  
Larry L. Howell
Keyword(s):  
Rigid Body ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Type Synthesis ◽  
Simplified Approach ◽  
Design Procedures ◽  
Synthesis Techniques ◽  
Design Solutions ◽  
Synthesis Methodology

Abstract The formulation of design procedures for rigid-body mechanisms has benefited from the application of type-synthesis techniques. Therefore, with modifications to allow for inclusions of compliance, type synthesis is seen as a useful tool in the design of compliant mechanisms. Previous efforts have developed methods that result in a large number of possible design solutions to a given problem. This paper deals primarily with the development of a simplified compliant-mechanism type-synthesis methodology that limits the number of design solutions considered. The techniques are derived by modifying existing compliant mechanism type-synthesis techniques to yield a simpler model with greater pragmatic value.

Classification of Compliant Mechanisms and Determination of the Degrees of Freedom Using the Concepts of Compliance Number and Pseudo-Rigid-Body Model

2019 ◽  
Author(s):  
Pratheek Bagivalu Prasanna ◽  
Ashok Midha ◽  
Sushrut G. Bapat
Keyword(s):  
Rigid Body ◽  
Degrees Of Freedom ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Body Model ◽  
Active Compliance ◽  
Kinematic Behavior ◽  
Rigid Body Model

Abstract Understanding the kinematic properties of a compliant mechanism has always proved to be a challenge. A concept of compliance number offered earlier emphasized the development of terminology that aided in its determination. A method to evaluate the elastic degrees of freedom associated with the flexible segments/links of a compliant mechanism using the pseudo-rigid-body model (PRBM) concept is provided. In this process, two distinct classes of compliant mechanisms are developed involving: (i) Active Compliance and (ii) Passive Compliance. Furthermore, these also aid in a better characterization of the kinematic behavior of a compliant mechanism. A more lucid interpretation of the significance of compliance number is provided. Applications of this method to both active and passive compliant mechanisms are exemplified. Finally, an experimental procedure that aids in visualizing the degrees of freedom as calculated is presented.

A Methodology for Determining Static Mode Shapes of a Compliant Mechanism Using the Pseudo-Rigid-Body Model (PRBM) Concept and the Degrees-of-Freedom Analysis

2019 ◽  
Author(s):  
Sushrut G. Bapat ◽  
Pratheek Bagivalu Prasanna ◽  
Ashok Midha
Keyword(s):  
Rigid Body ◽  
Degrees Of Freedom ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Mode Shapes ◽  
Model Concept ◽  
Static Mode ◽  
Displacement Boundary ◽  
Body Model ◽  
Rigid Body Model

Abstract Traditionally, the deflected configuration of compliant segments is determined through rigorous mathematical analysis using Newtonian mechanics. Application of these principles in evaluating the deformed configuration of compliant mechanisms, containing a variety of segment types, becomes cumbersome. This paper introduces a methodology to determine the expected deflected configuration(s) of a compliant mechanism, for a given set of load and/or displacement boundary conditions. The method utilizes the principle of minimum total potential energy, in conjunction with the degrees-of-freedom analysis and the pseudo-rigid-body model concept. The static mode shape(s) of compliant segments are integrated in identifying the possible functional configuration(s) of a given compliant mechanism’s structural configuration. The methodology, in turn, also facilitates the in situ determination of the deformed configuration of the constituent compliant segments. It thus assists in the identification of an appropriate pseudo-rigid-body model for design and analysis of a compliant mechanism.

Conceptual designs of multi-degree of freedom compliant parallel manipulators composed of wire-beam based compliant mechanisms

2014 ◽  
Vol 229 (3) ◽  
pp. 538-555 ◽  
Author(s):  
Guangbo Hao ◽  
Haiyang Li
Keyword(s):  
Rigid Body ◽  
Building Block ◽  
Compliant Mechanisms ◽  
Building Blocks ◽  
Parallel Manipulators ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Conceptual Designs ◽  
Rigid Body Model ◽  
Block Based

This paper proposes conceptual designs of multi-degree(s) of freedom (DOF) compliant parallel manipulators (CPMs) including 3-DOF translational CPMs and 6-DOF CPMs using a building block based pseudo-rigid-body-model (PRBM) approach. The proposed multi-DOF CPMs are composed of wire-beam based compliant mechanisms (WBBCMs) as distributed-compliance compliant building blocks (CBBs). Firstly, a comprehensive literature review for the design approaches of compliant mechanisms is conducted, and a building block based PRBM is then presented, which replaces the traditional kinematic sub-chain with an appropriate multi-DOF CBB. In order to obtain the decoupled 3-DOF translational CPMs (XYZ CPMs), two classes of kinematically decoupled 3-PPPR (P: prismatic joint, R: revolute joint) translational parallel mechanisms (TPMs) and 3-PPPRR TPMs are identified based on the type synthesis of rigid-body parallel mechanisms, and WBBCMs as the associated CBBs are further designed. Via replacing the traditional actuated P joint and the traditional passive PPR/PPRR sub-chain in each leg of the 3-DOF TPM with the counterpart CBBs (i.e. WBBCMs), a number of decoupled XYZ CPMs are obtained by appropriate arrangements. In order to obtain the decoupled 6-DOF CPMs, an orthogonally-arranged decoupled 6-PSS (S: spherical joint) parallel mechanism is first identified, and then two example 6-DOF CPMs are proposed by the building block based PRBM method. It is shown that, among these designs, two types of monolithic XYZ CPM designs with extended life have been presented.

On the Nomenclature, Classification, and Abstractions of Compliant Mechanisms

1994 ◽  
Vol 116 (1) ◽  
pp. 270-279 ◽  
Author(s):  
A. Midha ◽  
T. W. Norton ◽  
L. L. Howell
Keyword(s):  
Rigid Body ◽  
Current Literature ◽  
Compliant Mechanisms ◽  
Efficient Design ◽  
Concerted Effort ◽  
Research Activity ◽  
Levels Of Abstraction ◽  
Standard Nomenclature ◽  
The Past ◽  
Systematic Development

Compliant mechanisms, unlike rigid-body mechanisms, gain some or all of their mobility from the flexibility of their members. Complaint mechanisms are desirable since they require fewer parts, and have less wear, noise, and backlash than their rigid-body counterpart mechanisms. The field of compliant mechanisms is expected to continue to grow as materials with superior properties are developed. Inasmuch as evolution of efficient design techniques is viewed as an essential research activity, a parallel, systematic development of appropriate vocabulary (nomenclature, classification, etc.) is of primary importance. This paper proposes a standard nomenclature for the components of compliant mechanisms and discusses the relevant issues involved in this process. Definitions for components, such as “links” and “joints,” remove ambiguity that has been associated with these terms in the past. Names and diagrams are discussed, and are shown to be similar because they represent “abstractions” of the same mechanisms. The concept of “levels of abstraction” is introduced, and common levels of abstraction are identified. A concerted effort is made to be consistent with current literature on both rigid-body mechanisms and compliant mechanisms whenever possible.

On the Nomenclature and Classification of Compliant Mechanisms: The Components of Mechanisms

1992 ◽  
Author(s):  
Ashok Midha ◽  
Tony W. Norton ◽  
Larry L. Howell
Keyword(s):  
Rigid Body ◽  
Current Literature ◽  
Compliant Mechanisms ◽  
Efficient Design ◽  
Concerted Effort ◽  
Research Activity ◽  
The Past ◽  
Systematic Development ◽  
Body Joints

Abstract Compliant mechanisms gain some or all of their mobility from the flexibility of their members rather than from rigid-body joints only. Compliant mechanisms are desirable since they require fewer parts, and have less wear, noise, and backlash than their rigid-body counterpart mechanisms. The field of compliant mechanisms is important, and is expected to continue to grow as materials with superior properties are developed. Inasmuch as evolution of efficient design techniques is viewed as essential research activity, a parallel, systematic development of appropriate vocabulary (nomenclature, classification, etc.) is of primary importance. This paper proposes standard nomenclature for the components of compliant mechanisms and discusses the relevant issues involved in this process. Definitions for components, such as “links” and “joints,” remove ambiguity that has been associated with these terms in the past. A concerted effort is made to be consistent with current literature on both rigid-body mechanisms and compliant mechanisms whenever possible.

A Methodology for Determining Static Mode Shapes of a Compliant Mechanism Using the Pseudo-Rigid-Body Model Concept and the Degrees-Of-Freedom Analysis

2020 ◽  
Vol 12 (2) ◽  
Author(s):  
Pratheek Bagivalu Prasanna ◽  
Sushrut G. Bapat ◽  
Ashok Midha ◽  
Vamsi Lodagala
Keyword(s):  
Rigid Body ◽  
Degrees Of Freedom ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Mode Shapes ◽  
Model Concept ◽  
Static Mode ◽  
Displacement Boundary ◽  
Body Model ◽  
Rigid Body Model

Abstract Traditionally, the deflected configuration of compliant segments is determined through rigorous mathematical analysis using Newtonian mechanics. Application of this approach in evaluating the deformed configuration of compliant mechanisms, containing a variety of segment types, becomes cumbersome. This paper introduces a methodology to determine the possible deflected configuration(s) of a compliant mechanism, for a given set of load and/or displacement boundary conditions. The methodology utilizes the principle of minimum potential energy, in conjunction with the degrees-of-freedom analysis and the pseudo-rigid-body model concept. The static mode shape(s) of compliant segments are integrated in identifying the possible deflected configuration(s) of a given compliant mechanism. The methodology facilitates the in situ determination of the possible deformed configuration(s) of the compliant mechanism and its constituent segments. This, in turn, assists in the important task of identifying an appropriate pseudo-rigid-body model for the design and analysis of a compliant mechanism. The proposed methodology is illustrated with examples, and supported with experimental validation.

A Numerical Method for Position Analysis of Compliant Mechanisms With More Degrees of Freedom Than Inputs

2010 ◽  
Author(s):  
Quentin T. Aten ◽  
Shannon A. Zirbel ◽  
Brian D. Jensen ◽  
Larry L. Howell
Keyword(s):  
Potential Energy ◽  
Rigid Body ◽  
Equilibrium Position ◽  
Degrees Of Freedom ◽  
Compliant Mechanisms ◽  
Virtual Work ◽  
Compliant Mechanism ◽  
Loop Equation ◽  
Body Model ◽  
Rigid Body Model

An under-actuated or underconstrained compliant mechanism may have a determined equilibrium position because its energy storage elements cause a position of local minimum potential energy. The minimization of potential energy (MinPE) method is a numerical approach to finding the equilibrium position of compliant mechanisms with more degrees of freedom (DOF) than inputs. Given the pseudo-rigid-body model of a compliant mechanism, the MinPE method finds the equilibrium position by solving a constrained optimization problem: minimize the potential energy stored in the mechanism, subject to the mechanism’s vector loop equation(s) being equal to zero. The MinPE method agrees with the method of virtual work for position and force determination for under-actuated 1-DOF and 2-DOF pseudo-rigid-body models. Experimental force-deflection data is presented for a fully compliant constant-force mechanism. Because the mechanism’s behavior is not adequately modeled using a 1-DOF pseudo-rigid-body model, a 13-DOF pseudo-rigid-body model is developed and solved using the MinPE method. The MinPE solution is shown to agree well with non-linear finite element analysis and experimental force-displacement data.

Methodology for the Design of Compliant Mechanisms Employing Type Synthesis Techniques With Example

1994 ◽  
Author(s):  
Morgan D. Murphy ◽  
Ashok Midha ◽  
Larry L. Howell
Keyword(s):  
Rigid Body ◽  
Compliant Mechanisms ◽  
Design Procedure ◽  
Type Synthesis ◽  
Design Procedures ◽  
Rigid Link ◽  
Synthesis Techniques ◽  
Determine Mechanism

Abstract Type synthesis of rigid-link mechanisms provides a means to determine mechanism topologies before considering link dimensions. The formulation of design procedures for rigid-body mechanisms has benefited from the application of type synthesis techniques. Therefore, type synthesis is seen as a useful tool in the development of design procedures for compliant mechanisms as well. The focus of this paper is to propose and exemplify a design procedure for compliant mechanisms that employs the type synthesis techniques developed for compliant mechanisms.

The Topological Analysis of Compliant Mechanisms

1994 ◽  
Author(s):  
Morgan D. Murphy ◽  
Ashok Midha ◽  
Larry L. Howell
Keyword(s):  
Rigid Body ◽  
Systematic Approach ◽  
Compliant Mechanisms ◽  
Topological Analysis ◽  
Synthesis Process ◽  
Second Phase ◽  
Functional Requirements ◽  
Type Synthesis ◽  
Body Type ◽  
Synthesis Of Mechanisms

Abstract Following the topological synthesis of mechanisms, a topological analysis constitutes the second phase of the type-synthesis process. Topological analysis involves investigating distinct ways of specifying inputs, outputs and joint types to satisfy the functional requirements. For compliant mechanisms, the number of possible input combinations is typically much greater than for their rigid-body counterparts. Therefore, a systematic approach to input specification is required. This paper deals primarily with the development of a systematic input specification procedure for compliant mechanisms, while building on the rigid-body type-synthesis techniques and the terminology previously established for compliant elements. The techniques developed are straightforward and may be easily automated.

Sign in / Sign up

Export Citation Format

Share Document