An Energy Approach to a 2DOF Compliant Parallel Mechanism With Self-Guiding Statically-Balanced Straight-Line Behavior

2010 ◽  
Author(s):  
Emile J. Rosenberg ◽  
Giuseppe Radaelli ◽  
Just L. Herder
Keyword(s):  
Structural Design ◽  
Compliant Mechanisms ◽  
Element Model ◽  
Energy Approach ◽  
Straight Line ◽  
Synthesis Tool ◽  
Rigid Body Model ◽  
Physical Prototype ◽  
Manufacturing Techniques ◽  
Cost Efficient

This paper presents a novel straight-line self-guiding statically-balanced mechanism which reflects on the advantages of lumped compliant mechanisms. The forthcoming structural design is conceived with an energy approach for static balancing of mechanisms. In this paper the application and effectiveness of the energy approach as a synthesis tool is validated. Moreover the paper demonstrates the translation from pseudo-rigid body model to lumped compliance in statically-balanced mechanisms. A physical prototype and a finite-element model served to evaluate the conceptual design. Manufacturing techniques are suggested for rapid, light-weight and cost-efficient prototyping. The presented self-guiding mechanism is statically-balanced along its straight-line range of motion while showing stable behavior in other directions.

A Pseudo Rigid Body Model of a Single Vertex Compliant-Facet Origami Mechanism (SV-COFOM)

2016 ◽  
Author(s):  
Jelle Rommers ◽  
Giuseppe Radaelli ◽  
Just Herder
Keyword(s):  
Rigid Body ◽  
Computational Cost ◽  
Element Model ◽  
Design Tool ◽  
Single Vertex ◽  
Starting Point ◽  
Rigid Body Model ◽  
Cost Efficient ◽  
The Moment ◽  
Planar Fabrication

Recently, there has been an increased interest in origami art from a mechanism design perspective. The deployable nature and the planar fabrication method inherent to origami provide potential for space and cost efficient mechanisms. In this paper, a novel type of origami mechanisms is proposed in which the compliance of the facets is used to incorporate spring behavior: Compliant Facet Origami Mechanisms (COFOMs). A simple model that computes the moment characteristic of a Single Vertex COFOM has been proposed, using a semi-spatial version of the Pseudo-Rigid Body (PRB) theory to model bending of the facets. The performance of this PRB model has been evaluated numerically and experimentally, and showed performance comparable to a Finite Element model with 122 elements. The PRB model is a potential starting point for a design tool which would provide an intuitive way of designing this type of mechanisms including their spring behavior, with very low computational cost.

scholarly journals Static behavior of weighing cells

2018 ◽  
Vol 7 (2) ◽  
pp. 587-600 ◽  
Author(s):  
Maximilian Darnieder ◽  
Markus Pabst ◽  
Ronny Wenig ◽  
Lena Zentner ◽  
René Theska ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Element Model ◽  
Novel Approach ◽  
Stiffness Characteristic ◽  
Highly Sensitive ◽  
Rigid Body Model ◽  
Mechanical Models ◽  
Parametric Studies

Abstract. Compliant mechanisms in precision weighing technology are highly sensitive mechanical systems with continuously rising demands for performance in terms of resolution and measurement uncertainty. The systematic combination of adjustment measures represents a promising option for the enhancement of weighing cells which is not yet fully exhausted. A novel adjustment concept for electromagnetic force compensated weighing cells designed for 1 kg mass standards is introduced. The effect on the mechanical behavior is analyzed in detail using a planar compliant mechanism with semi-circular flexure hinges. Design equations for a first layout of the mechanical system are derived from a linearized rigid body model. Existing adjustment concepts for the stiffness characteristic and the sensitivity to quasi-static ground tilt are included. They are extended by the novel approach to attach trim weights to the levers of the linear guide. Based on this concept, an optimal design for the weighing cell is determined. The comparison with a finite element model reveals further effects given by the more precise description of the mechanical behavior. By parametric studies of the adjustment parameters in the mechanical models, it is shown that the stiffness and tilt sensitivity can be reduced significantly compared to the non-adjusted weighing cell. The principal correlation of the trim weights and their effect on the mechanical properties is experimentally verified using a commercially available weighing cell.

Dynamic Response of Compliant Mechanisms Using the Pseudo-Rigid-Body Model

1997 ◽  
Author(s):  
Scott M. Lyon ◽  
Mark S. Evans ◽  
Paul A. Erickson ◽  
Larry L. Howell
Keyword(s):  
Dynamic Response ◽  
Rigid Body ◽  
Nonlinear Analysis ◽  
Natural Frequencies ◽  
Compliant Mechanisms ◽  
Experimental Results ◽  
Body Model ◽  
Straight Line ◽  
Model Predictions ◽  
Rigid Body Model

Abstract The pseudo-rigid-body modeling technique is used to simplify the nonlinear analysis of compliant mechanisms. This paper presents the first work that investigates the possibility of using the pseudo-rigid-body model to predict the dynamic response of compliant mechanisms. Four different configurations of the parallel-guiding mechanism are modeled and tested, as well as two configurations of compliant straight-line mechanisms. The model predictions of the first natural frequencies were compared with experimental results for all six mechanism configurations. The model predictions are within 9% of the experimental results for all cases.

A Compliant Straight-Line Shock Absorption Mechanism Using a Viscoelastic Pseudo-Rigid Body Model

2009 ◽  
Author(s):  
Carl A. Nelson
Keyword(s):  
Energy Dissipation ◽  
System Dynamics ◽  
Rigid Body ◽  
Large Deflection ◽  
Compliant Mechanisms ◽  
Force Analysis ◽  
Absorption Mechanism ◽  
Body Model ◽  
Straight Line ◽  
Rigid Body Model

A compliant suspension linkage based on the Peaucellier mechanism is presented. The suspension uses large-deflection viscoelastic beams to achieve straight-line motion and to provide energy dissipation. Kinematics and force analysis of the linkage are presented. In preparing to simulate the system dynamics, it was noticed that no adaptation of the pseudo-rigid body model for viscoelastic beams had been previously presented. Therefore, a new general approach for modeling viscoelastic, large-deflection beams in compliant mechanisms is described within the context of the pseudo-rigid-body model. This method is applied in simulation of the Peaucellier-based compliant suspension under a variety of input conditions.

Modeling Large Spatial Deflections of Slender Beams of Rectangular Cross Sections in Compliant Mechanisms

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Ruiyu Bai ◽  
Guimin Chen
Keyword(s):  
Power Series ◽  
Cross Sections ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Rectangular Cross Section ◽  
Element Model ◽  
Flexible Beams ◽  
Rigid Body Model ◽  
Slender Beams ◽  
Nonlinear Finite Element Model

Abstract Modeling large spatial deflections of flexible beams has been one of the most challenging problems in the research of compliant mechanism. This study presents an approach called chained power series model for modeling large spatial defections of flexible beams with uniform rectangular cross section. This approach is based on the power series model developed in our previous work for modeling spatial deflections of rectangular beams in the intermediate deflection range. The chained power series model splits a rectangular beam into several elements and models each element by the power series model, and then, the deflections of all elements are assembled to form the deflection of the beam through transformations using quaternions. The effectiveness of the approach is demonstrated by comparing with the nonlinear finite element model preformed in ansys and the chained 3D pseudo-rigid-body model. Several examples are demonstrated to show the capability of the chained power series model for solving the deflections of rectangular beams in compliant mechanisms.

Prediction of the First Modal Frequency of Compliant Mechanisms Using the Pseudo-Rigid-Body Model

1999 ◽  
Vol 121 (2) ◽  
pp. 309-313 ◽  
Author(s):  
S. M. Lyon ◽  
P. A. Erickson ◽  
M. S. Evans ◽  
L. L. Howell
Keyword(s):  
Rigid Body ◽  
Natural Frequencies ◽  
Compliant Mechanisms ◽  
Experimental Results ◽  
Modal Frequency ◽  
Body Model ◽  
Modal Response ◽  
Straight Line ◽  
Model Predictions ◽  
Rigid Body Model

The pseudo-rigid-body modeling technique is used to simplify the nonlinear analysis of compliant mechanisms. This paper presents the first work that investigates the possibility of using the pseudo-rigid-body model to predict the first modal response of compliant mechanisms. Four different configurations of the parallel-guiding mechanism are modeled and tested, as well as two configurations of compliant straight-line mechanisms. The model predictions of the first natural frequencies were compared with experimental results for all six mechanism configurations. The model predictions are within 9 percent of the experimental results for all cases.

scholarly journals Analytical Modeling and Simulation of S-Drive Piezoelectric Actuators

Actuators ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 87
Author(s):  
Nicholas A. Jones ◽  
Jason Clark
Keyword(s):  
Element Model ◽  
Mechanical Efficiency ◽  
Compact Model ◽  
High Frequency Response ◽  
Macro Scale ◽  
Piezoelectric Structure ◽  
Modern Manufacturing ◽  
Manufacturing Techniques ◽  
Piezoelectric Structures ◽  
Improve Device

This paper presents a structural geometry for increasing piezoelectric deformation, which is suitable for both micro- and macro-scale applications. New and versatile microstructure geometries for actuators can improve device performance, and piezoelectric designs benefit from a high-frequency response, power density, and efficiency, making them a viable choice for a variety of applications. Previous works have presented piezoelectric structures capable of this amplification, but few are well-suited to planar manufacturing. In addition to this manufacturing difficulty, a large number of designs cannot be chained into longer elements, preventing them from operating at the macro-scale. By optimizing for both modern manufacturing techniques and composability, this structure excels as an option for a variety of macro- and micro-applications. This paper presents an analytical compact model of a novel dual-bimorph piezoelectric structure, and shows that this compact model is within 2% of a computer-distributed element model. Furthermore it compares the actuator’s theoretical performance to that of a modern actuator, showing that this actuator trades mechanical efficiency for compactness and weight savings.

A Simple and Accurate Method for Determining Large Deflections in Compliant Mechanisms Subjected to End Forces and Moments

1998 ◽  
Vol 120 (3) ◽  
pp. 392-400 ◽  
Author(s):  
A. Saxena ◽  
S. N. Kramer
Keyword(s):  
Rigid Body ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Elliptic Integral ◽  
Beam Equation ◽  
Large Deflections ◽  
Euler Beam ◽  
Body Model ◽  
Rigid Body Model ◽  
Analysis And Synthesis

Compliant members in flexible link mechanisms undergo large deflections when subjected to external loads. Because of this fact, traditional methods of deflection analysis do not apply. Since the nonlinearities introduced by these large deflections make the system comprising such members difficult to solve, parametric deflection approximations are deemed helpful in the analysis and synthesis of compliant mechanisms. This is accomplished by representing the compliant mechanism as a pseudo-rigid-body model. A wealth of analysis and synthesis techniques available for rigid-body mechanisms thus become amenable to the design of compliant mechanisms. In this paper, a pseudo-rigid-body model is developed and solved for the tip deflection of flexible beams for combined end loads. A numerical integration technique using quadrature formulae has been employed to solve the large deflection Bernoulli-Euler beam equation for the tip deflection. Implementation of this scheme is simpler than the elliptic integral formulation and provides very accurate results. An example for the synthesis of a compliant mechanism using the proposed model is also presented.

A Simple and Accurate Method for Determining Large Deflections in Complaint Mechanisms Subjected to End Forces and Moments

1998 ◽  
Author(s):  
A. Saxena ◽  
Steven N. Kramer
Keyword(s):  
Rigid Body ◽  
Numerical Integration ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Beam Equation ◽  
Integration Scheme ◽  
Large Deflections ◽  
Body Model ◽  
Rigid Body Model ◽  
Analysis And Synthesis

Abstract Compliant members in flexible link mechanisms undergo large deflections when subjected to external loads for which, traditional methods of deflection analysis do not apply Nonlinearities introduced by these large deflections make the system comprising such members difficult to solve Parametric deflection approximations are then deemed helpful in the analysis and synthesis of compliant mechanisms This is accomplished by seeking the pseudo-rigid-body model representation of the compliant mechanism A wealth of analysis and synthesis techniques available for rigid-body mechanisms thus become amenable to the design of compliant mechanisms In this paper, a pseudo-rigid-body model is developed and solved for the tip deflection of flexible beams for combined end loads with positive end moments A numerical integration technique using quadrature formulae has been employed to solve the nonlinear Bernoulli-Euler beam equation for the tip deflection Implementation of this scheme is relatively simpler than the elliptic integral formulation and provides nearly accurate results Results of the numerical integration scheme are compared with the beam finite element analysis An example for the synthesis of a compliant mechanism using the proposed model is also presented.

Evaluation of Equivalent Spring Stiffness for Use in a Pseudo-Rigid-Body Model of Large-Deflection Compliant Mechanisms

1994 ◽  
Author(s):  
Larry L. Howell ◽  
Ashok Midha
Keyword(s):  
Rigid Body ◽  
Large Deflection ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Spring Stiffness ◽  
Model Concept ◽  
Analysis And Design ◽  
Body Model ◽  
Rigid Body Model ◽  
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. More efficient and usable analysis and design techniques are needed before the advantages of compliant mechanisms can be fully utilized. In an earlier work, a pseudo-rigid-body model concept, corresponding to an end-loaded geometrically nonlinear, large-deflection beam, was developed to help fulfill this need. In this paper, the pseudo-rigid-body equivalent spring stiffness is investigated and new modeling equations are proposed. The result is a simplified method of modeling the force/deflection relationships of large-deflection members in compliant mechanisms. Flexible segments which maintain a constant end angle are discussed, and an example mechanism is analyzed. The resulting models are valuable in the visualization of the motion of large-deflection systems, as well as the quick and efficient evaluation and optimization of compliant mechanism designs.

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