Identification of Compliant Pseudo-Rigid-Body Four-Link Mechanism Configurations Resulting in Bistable Behavior

2003 ◽  
Vol 125 (4) ◽  
pp. 701-708 ◽  
Author(s):  
Brian D. Jensen ◽  
Larry L. Howell
Keyword(s):  
Energy Storage ◽  
Rigid Body ◽  
Mechanism Design ◽  
Bistable Behavior ◽  
Strongly Coupled ◽  
Present Design ◽  
Stable Equilibria ◽  
Motion Characteristics ◽  
Bistable Mechanism ◽  
Design Challenges

Bistable mechanisms, which have two stable equilibria within their range of motion, are important parts of a wide variety of systems, such as closures, valves, switches, and clasps. Compliant bistable mechanisms present design challenges because the mechanism’s energy storage and motion characteristics are strongly coupled and must be considered simultaneously. This paper studies compliant bistable mechanisms which may be modeled as four-link mechanisms with a torsional spring at one joint. Theory is developed to predict compliant and rigid-body mechanism configurations which guarantee bistable behavior. With this knowledge, designers can largely uncouple the motion and energy storage requirements of a bistable mechanism design problem. Examples demonstrate the power of the theory in bistable mechanism design.

Identification of Compliant Pseudo-Rigid-Body Mechanism Configurations Resulting in Bistable Behavior

2000 ◽  
Author(s):  
Brian D. Jensen ◽  
Larry L. Howell
Keyword(s):  
Energy Storage ◽  
Rigid Body ◽  
Mechanism Design ◽  
Bistable Behavior ◽  
Strongly Coupled ◽  
Present Design ◽  
Stable Equilibria ◽  
Motion Characteristics ◽  
Bistable Mechanism ◽  
Design Challenges

Abstract Bistable mechanisms, which have two stable equilibria within their range of motion, are important parts of a wide variety of systems, such as closures, valves, switches, and clasps. Compliant bistable mechanisms present design challenges because the mechanism’s energy storage and motion characteristics are strongly coupled and must be considered simultaneously. This paper studies compliant bistable mechanisms which may be modeled as four-link mechanisms with a torsional spring at one joint. Theory is developed to predict compliant and rigid-body mechanism configurations which guarantee bistable behavior. With this knowledge, designers can largely uncouple the motion and energy storage requirements of a bistable mechanism design problem. Examples demonstrate the power of the theory in bistable mechanism design.

Bistable Compliant Four-Bar Mechanisms With a Single Torsional Spring

2006 ◽  
Author(s):  
Adarsh Mavanthoor ◽  
Ashok Midha
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Mechanism Design ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Stored Energy ◽  
Element Analysis ◽  
Bistable Behavior ◽  
Torsional Spring ◽  
Bistable Mechanism

Significant reduction in cost and time of bistable mechanism design can be achieved by understanding their bistable behavior. This paper presents bistable compliant mechanisms whose pseudo-rigid-body models (PRBM) are four-bar mechanisms with a torsional spring. Stable and unstable equilibrium positions are calculated for such four-bar mechanisms, defining their bistable behavior for all possible permutations of torsional spring locations. Finite Element Analysis (FEA) and simulation is used to illustrate the bistable behavior of a compliant mechanism with a straight compliant member, using stored energy plots. These results, along with the four-bar and the compliant mechanism information, can then be used to design a bistable compliant mechanism to meet specified requirements.

Bistable Configurations of Compliant Mechanisms Modeled Using Four Links and Translational Joints

2004 ◽  
Vol 126 (4) ◽  
pp. 657-666 ◽  
Author(s):  
Brian D. Jensen ◽  
Larry L. Howell
Keyword(s):  
Energy Storage ◽  
Prior Knowledge ◽  
Compliant Mechanisms ◽  
Power Input ◽  
Local Minima ◽  
Stored Energy ◽  
Bistable Behavior ◽  
Micro Electro Mechanical Systems ◽  
Bistable Mechanism ◽  
Mechanical Devices

Bistable mechanical devices remain stable in two distinct positions without power input. They find application in valves, switches, closures, and clasps. Mechanically bistable behavior results from the storage and release of energy, typically in springs, with stable positions occurring at local minima of stored energy. Compliant mechanisms offer an elegant way to achieve this behavior by incorporating both motion and energy storage into the same flexible element. Interest in compliant bistable mechanisms has also recently increased because of the advantages of bistable behavior in many micro-electro-mechanical systems (MEMS). Design of compliant or rigid-body bistable mechanisms typically requires simultaneous consideration of both energy storage and motion requirements. This paper simplifies this process by developing theory that provides prior knowledge of mechanism configurations that guarantee bistable behavior. Configurations which include one or more translational, or slider, joints are studied in this work. Several different mechanism types are analyzed to determine compliant segment placement that will ensure bistable mechanism operation. Examples demonstrate the power of the theory in design.

An Investigation Into Compliant Bistable Mechanisms

1998 ◽  
Author(s):  
Patrick G. Opdahl ◽  
Brian D. Jensen ◽  
Larry L. Howell
Keyword(s):  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Paper Briefly ◽  
Bistable Behavior ◽  
New Class ◽  
Force And Motion ◽  
Predicted Values ◽  
Motion Characteristics ◽  
Bistable Mechanism ◽  
Mechanism Theory

Abstract This paper proposes a new class of bistable mechanisms: compliant bistable mechanisms. These mechanisms gain their bistable behavior from the energy stored in the flexible segments which deflect to allow mechanism motion. This approach integrates desired mechanism motion and energy storage to create bistable mechanisms with dramatically reduced part count compared to traditional mechanisms incorporating rigid links, joints, and springs. This paper briefly reviews bistable mechanism theory, introduces some additional bistable mechanism characteristics, and integrates this theory with compliant mechanism theory. The resulting theory of bistable compliant mechanisms is validated by measuring the force and motion characteristics of several test mechanisms and comparing them to predicted values.

A Compliant Bistable Mechanism Design Incorporating Elastica Buckling Beam Theory and Pseudo-Rigid-Body Model

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Ümit Sönmez ◽  
Cem C. Tutum
Keyword(s):  
Rigid Body ◽  
Mechanism Design ◽  
Kinematic Analysis ◽  
Compliant Mechanism ◽  
Beam Theory ◽  
Algebraic Equations ◽  
Body Model ◽  
Buckling Beam ◽  
Rigid Body Model ◽  
Bistable Mechanism

In this work, a new compliant bistable mechanism design is introduced. The combined use of pseudo-rigid-body model (PRBM) and the Elastica buckling theory is presented for the first time to analyze the new design. This mechanism consists of the large deflecting straight beams, buckling beams, and a slider. The kinematic analysis of this new mechanism is studied, using nonlinear Elastica buckling beam theory, the PRBM of a large deflecting cantilever beam, the vector loop closure equations, and numerically solving nonlinear algebraic equations. A design method of the bistable mechanism in microdimensions is investigated by changing the relative stiffness of the flexible beams. The actuation force versus displacement characteristics of several cases is explored and the full simulation results of one of the cases are presented. This paper demonstrates the united application of the PRBM and the buckling Elastica solution for an original compliant mechanism kinematic analysis. New compliant mechanism designs are presented to highlight where such combined kinematic analysis is required.

Ultralight supercapacitors utilizing waste cotton pads for wearable energy storage

2018 ◽  
Vol 47 (46) ◽  
pp. 16684-16695 ◽  
Author(s):  
Yang Lu ◽  
Weixiao Wang ◽  
Yange Wang ◽  
Menglong Zhao ◽  
Jinru Lv ◽  
...  
Keyword(s):  
Energy Storage ◽  
Potential Application ◽  
Storage Systems ◽  
Energy Storage Systems ◽  
Strongly Coupled ◽  
Flexible Supercapacitor

Ultralight, flexible and renewable supercapacitors based on MnO2 nanosheets strongly coupled with a PPy layer coated on discarded cotton pads as electrodes have been developed. The flexible supercapacitor is ready for a potential application in wearable energy storage systems.

Kinematics Simulation Analysis of Turn-Milling Center Based on Virtual Prototype

2010 ◽  
Vol 43 ◽  
pp. 683-686
Author(s):  
Li Da Zhu ◽  
Jia Ying Pei ◽  
Tian Biao Yu ◽  
Wan Shan Wang
Keyword(s):  
Mechanism Design ◽  
Inverse Kinematics ◽  
Development Time ◽  
Simulation Analysis ◽  
Forward Kinematics ◽  
Optimized Design ◽  
Kinematics Simulation ◽  
Physical Prototype ◽  
Motion Characteristics ◽  
Turn Milling

In order to analyze the motion characteristics of turn-milling center, it’s prototype is modeled and spiral motion is simulated and analyzed to get curves of displacement and velocity in forward kinematics and inverse kinematics. The rationality and applicability of mechanism design is verificated to provide the basis of fast optimized design of turn-milling center. So the method can forecast and improve before physical prototype manufacturing to ensure design feasibility and save development time.

Utilizing a Classification Scheme to Facilitate Rigid-Body Replacement for Compliant Mechanism Design

2010 ◽  
Author(s):  
Brian M. Olsen ◽  
Yanal Issac ◽  
Larry L. Howell ◽  
Spencer P. Magleby
Keyword(s):  
Rigid Body ◽  
Mechanism Design ◽  
Classification Scheme ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
The Other ◽  
Design Approach ◽  
Compliant Mechanism Design

The knowledge related to the synthesis and analysis of compliant mechanisms continues to grow and mature. Building on this growth, a classification scheme has been established to categorize compliant elements and mechanisms in a manner that engineers can incorporate compliance into their designs. This paper demonstrates a design approach engineers can use to convert an existing rigid-body mechanism into a compliant mechanism by using an established classification scheme. This approach proposes two possible techniques that use rigid-body replacement synthesis in conjunction with a compliant mechanism classification scheme. One technique replaces rigid-body elements with a respective compliant element. The other technique replaces a complex rigid-body mechanism by decomposing the mechanism into simpler functions and then replacing a respective rigid-body mechanism with a compliant mechanism that has a similar functionality.

A Compliant Mechanism Design Methodology for Coupled and Uncoupled Systems, and Governing Free Choice Selection Considerations

2004 ◽  
Author(s):  
Ashok Midha ◽  
Yuvaraj Annamalai ◽  
Sharath K. Kolachalam
Keyword(s):  
Rigid Body ◽  
Design Methodology ◽  
Free Choice ◽  
Compliant Mechanisms ◽  
State Of The Art ◽  
Compliant Mechanism ◽  
Mechanism Synthesis ◽  
Strongly Coupled ◽  
Revolute Joints ◽  
Compliant Mechanism Design

Compliant mechanisms are defined as mechanisms that gain some, or all of their mobility from the flexibility of their members. Suitable use of pseudo-rigid-body models for compliant segments, and relying on the state-of-the-art knowledge of rigid-body mechanism synthesis types, greatly simplifies the design of compliant mechanisms. Assuming a pseudo-rigid-body four-bar mechanism, with one to four torsional springs located at the revolute joints to represent mechanism compliance, a simple, heuristic approach is provided to develop various compliant mechanism types. The synthesis with compliance method is used for three, four and five precision positions, with consideration of one to four torsional springs, to systematically develop design tables for standard mechanism synthesis types. These tables appropriately reflect the mechanism compliance by specification of either energy or torque. Examples are presented to demonstrate the use of weakly or strongly coupled sets of kinematic and energy/torque equations, as well as different compliant mechanism types in obtaining solutions.

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