Design of Adaptive and Controllable Compliant Systems With Embedded Actuators and Sensors

2009 ◽  
Vol 131 (11) ◽  
Author(s):  
Brian Trease ◽  
Sridhar Kota
Keyword(s):  
Compliant Mechanism ◽  
Systems Design ◽  
Maximum Energy ◽  
Topology Design ◽  
Simultaneous Optimization ◽  
System Response ◽  
Structural Topology ◽  
Element Analysis ◽  
Active Structure ◽  
Compliant Systems

We present a framework for the design of a compliant system, i.e., the concurrent design of a compliant mechanism with embedded actuators and sensors. Our methods simultaneously synthesize optimal structural topology and component placement for maximum energy efficiency and adaptive performance, while satisfying various weight and performance constraints. The goal of this research is to lay an algorithmic framework for distributed actuation and sensing within a compliant active structure. Key features of the methodology include (1) the simultaneous optimization of the location, orientation, and size of actuators (and sensors) concurrent with the compliant transmission topology, and (2) the implementation of controllability and observability concepts (both arising from consideration of control) in compliant systems design. The methods used include genetic algorithms, graph searches for connectivity, and multiple load cases implemented with linear finite element analysis. Actuators, modeled as both force generators and structural compliant elements, are included as topology variables in the optimization. The results from the controllability problem are used to motivate and describe the analogous extension to observability for sensing. Results are provided for several studies, including (1) concurrent actuator placement and topology design for a compliant amplifier, (2) a shape-morphing aircraft wing demonstration with three controlled output nodes, and (3) a load-distribution sensing wing structure with internal sensors. Central to this method is the concept of structure/component orthogonality, which refers to the unique system response for each component (actuator or sensor) it contains.

Synthesis of Adaptive and Controllable Compliant Systems With Embedded Actuators and Sensors

2006 ◽  
Author(s):  
Brian P. Trease ◽  
Sridhar Kota
Keyword(s):  
Compliant Mechanism ◽  
Systems Design ◽  
Maximum Energy ◽  
Topology Design ◽  
Simultaneous Optimization ◽  
System Response ◽  
Mathematical Framework ◽  
Structural Topology ◽  
Element Analysis ◽  
Compliant Systems

This paper presents a framework for the design of a compliant system; that is, the concurrent design of a compliant mechanism with embedded actuators and embedded sensors. We focus on methods that simultaneously synthesize optimal structural topology and placement of actuators and sensors for maximum energy efficiency and adaptive performance, while satisfying various weight and performance constraints. The goal of this research is to lay a scientific foundation and a mathematical framework for distributed actuation and sensing within a compliant active structure. Key features of the methodology include (1) the simultaneous optimization of the location, orientation, and size of actuators concurrent with the compliant transmission topology and (2) the concepts of controllability and observability that arise from the consideration of control, and their implementation in compliant systems design. The methods used include genetic algorithms, graph searches for connectivity, and multiple load cases implemented with linear finite element analysis. Actuators, modeled as both force generators and structural compliant elements, are included as topology variables in the optimization. Results are provided for several studies, including: (1) concurrent actuator placement and topology design for a compliant amplifier and (2) a shape-morphing aircraft wing demonstration with three controlled output nodes. Central to this method is the concept of structural orthogonality, which refers to the unique system response for each actuator it contains. Finally, the results from the controllability problem are used to motivate and describe the analogous extension to observability for sensing.

scholarly journals Topology Synthesis of Compliant Systems With Embedded Actuators and Sensors

2008 ◽  
Author(s):  
Brian Trease ◽  
Sridhar Kota
Keyword(s):  
Adaptive Systems ◽  
Compliant Mechanisms ◽  
Single Point ◽  
Sensor Placement ◽  
System Response ◽  
Structural Topology ◽  
Force Transmission ◽  
Basic Premise ◽  
Starting Point ◽  
Compliant Systems

The basic premise of a compliant system is the integration of motion/force transmission via elastic deformation with embedded actuation and sensing. Current electromechanical systems are generally fashioned in the rigid-and-discrete paradigm where one first designs a rigid structure with mechanical joints and then adds actuators and sensors, with the design of controls only following as an afterthought. The objective of this research is a systems approach to synthesis of mechanism, structure, actuation, and sensing, thereby advancing from traditional mechanical design to automated compliant system design. In previous studies of compliant mechanisms and their synthesis, single-actuator mechanisms have primarily been considered, with the determination of the actuator’s type, orientation, size, and location occurring outside of the automated design synthesis, at the designer’s option. A new algorithmic framework is presented, in which structural topology and actuator/sensor placement are simultaneously synthesized for adaptive performance. Significantly, this is not a traditional ad hoc method; sensor and actuator placement affect structural topology and vice versa. This is a continuation of our previously reported actuation-placement work [1–2], updated here to include the sensor placement co-synthesis and new tasks in addition to shape change. The methods used include genetic algorithms, graph searches for connectivity, and multiple load cases implemented with linear finite element analysis. Fundamental metrics for the inclusion of embedded components in a multifunctional compliant system are developed and investigated. The essential framework for the integration of controls with compliant mechanisms is established. Specifically, the concepts of controllability and observability, as redefined for compliant systems, are proven as a successful starting point for the design of multifunctional, adaptive systems. These concepts refer to the unique system response for each component (actuator or sensor) it contains. Results are presented for several problems, focusing on the application of shape-morphing aircraft structures. Through examples and design studies, the metrics and the methodology demonstrate that multiple, optimally-placed components indeed offer performance benefits for mechanical systems, in terms of multifunctional execution. Finally, the extension of controllability to address the problem of single-point multidegree-of-freedom manipulation is performed to show the generalized use of the new methodology in benefitting the design of compliant systems.

scholarly journals Genetic Algorithms As an Approach to Configuration and Topology Design

1993 ◽  
Author(s):  
Colin D. Chapman ◽  
Kazuhiro Saitou ◽  
Mark J. Jakiela
Keyword(s):  
Genetic Algorithm ◽  
Topology Optimization ◽  
Structural Optimization ◽  
Optimization Technique ◽  
Topology Design ◽  
Structural Topology Optimization ◽  
Structural Topology ◽  
Element Analysis ◽  
Structure Topology ◽  
Design Representation

Abstract The Genetic Algorithm, a search and optimization technique based on the theory of natural selection, is applied to problems of structural topology optimization. Given a structure’s boundary conditions and maximum allowable design domain, a discretized design representation is created. Populations of genetic algorithm “chromosomes” are then mapped into the design representation, creating potentially optimal structure topologies. Utilizing genetics-based operators such as crossover and mutation, generations of increasingly-desirable structure topologies are created. In this paper, the use of the genetic algorithm (GA) in structural topology optimization is presented. An overview of the genetic algorithm will describe the genetics-based representations and operators used in a typical genetic algorithm search. After defining topology optimization and its relation to the broader area of structural optimization, a review of previous research in GA-based and non-GA-based structural optimization is provided. The design representations, and methods for mapping genetic algorithm “chromosomes” into structure topology representations, are then detailed. Several examples of genetic algorithm-based structural topology optimization are provided: we address the optimization of beam cross-section topologies and cantilevered plate topologies, and we also investigate efficient techniques for using finite element analysis in a genetic algorithm-based search. Finally, a description of potential future work in genetic algorithm-based structural topology optimization is offered.

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.

Design of a Single-Acting Constant-Force Actuator Based on Dielectric Elastomers

2008 ◽  
Author(s):  
Giovanni Berselli ◽  
Rocco Vertechy ◽  
Gabriele Vassura ◽  
Vincenzo Parenti Castelli
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Compliant Mechanism ◽  
Structural Parameters ◽  
Dielectric Elastomer ◽  
Constant Force ◽  
Element Analysis ◽  
Body Model ◽  
Rigid Body Model ◽  
Supporting Frame

The interest in actuators based on dielectric elastomer films as a promising technology in robotic and mechatronic applications is increasing. The overall actuator performances are influenced by the design of both the active film and the film supporting frame. This paper presents a single-acting actuator which is capable of supplying a constant force over a given range of motion. The actuator is obtained by coupling a rectangular film of silicone dielectric elastomer with a monolithic frame designed to suitably modify the force generated by the dielectric elastomer film. The frame is a fully compliant mechanism whose main structural parameters are calculated using a pseudo-rigid-body model and then verified by finite element analysis. Simulations show promising performance of the proposed actuator.

scholarly journals Impact of residual stress evoked by pyramidal embossing on the magnetic material properties of non-oriented electrical steel

2021 ◽  
Author(s):  
Ines Gilch ◽  
Tobias Neuwirth ◽  
Benedikt Schauerte ◽  
Nora Leuning ◽  
Simon Sebold ◽  
...  
Keyword(s):  
Magnetic Material ◽  
Residual Stress ◽  
Magnetic Flux ◽  
Material Properties ◽  
Electrical Steel ◽  
Maximum Energy ◽  
Material Behavior ◽  
Electrical Machine ◽  
Element Analysis ◽  
Steel Sheets

AbstractTargeted magnetic flux guidance in the rotor cross section of rotational electrical machines is crucial for the machine’s efficiency. Cutouts in the electrical steel sheets are integrated in the rotor sheets for magnetic flux guidance. These cutouts create thin structures in the rotor sheets which limit the maximum achievable rotational speed under centrifugal forces and the maximum energy density of the rotating electrical machine. In this paper, embossing-induced residual stress, employing the magneto-mechanical Villari effect, is studied as an innovative and alternative flux barrier design with negligible mechanical material deterioration. The overall objective is to replace cutouts by embossings, increasing the mechanical strength of the rotor. The identification of suitable embossing geometries, distributions and methodologies for the local introduction of residual stress is a major challenge. This paper examines finely distributed pyramidal embossings and their effect on the magnetic material behavior. The study is based on simulation and measurements of specimen with a single line of twenty embossing points performed with different punch forces. The magnetic material behavior is analyzed using neutron grating interferometry and a single sheet tester. Numerical examinations using finite element analysis and microhardness measurements provide a more detailed understanding of the interaction of residual stress distribution and magnetic material properties. The results reveal that residual stress induced by embossing affects magnetic material properties. Process parameters can be applied to adjust the magnetic material deterioration and the effect of magnetic flux guidance.

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.

scholarly journals Finite Element Analysis of the Parthenon marble block- steel clamp system response under acceleration

ACTA IMEKO ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 155
Author(s):  
Zacharias Vangelatos ◽  
Michail Delagrammatikas ◽  
Olga Papadopoulou ◽  
Charalampos Titakis ◽  
Panayota Vassiliou
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Structural Engineering ◽  
Conservation Status ◽  
Intrinsic Stress ◽  
System Response ◽  
Confined Space ◽  
Structural System ◽  
Element Analysis ◽  
Scientific Fields

<p class="Abstract">Finite element analysis is employed to investigate the mechanical behaviour and failure scenarios of the marble block–steel clamp ancient masonry system utilised in the Parthenon (Athens Acropolis) under static loading analysis. The input data for the model are acquired by the laboratory testing of early 20th century restoration steel clamps, such as through tensile strength measurements and metallography, as well as bibliographic sources from various scientific fields (i.e. material properties, archaeometry, restoration, structural engineering and geology). Two different embedding materials (Portland cement mortar and lead), used for the nesting of the clamps, are examined under bending or stretching, induced by acceleration forces. The conservation status of the materials is taken into account by employing an intrinsic stress, as is the case when corrosion products build up in a confined space. The aim of this work is to provide a tool for the assessment of the conservation potential of the marble blocks in parts of the monument that require specific attention. Simulation results indicate the resilience of the Parthenon’s structural system under most examined scenarios and highlight the importance of intrinsic stresses, the existence of which may lead to the fracture of the marble blocks under otherwise harmless loading conditions.</p>

Design of a piezoelectric actuator and compliant mechanism combination for maximum energy efficiency

2005 ◽  
Vol 14 (6) ◽  
pp. 1421-1430 ◽  
Author(s):  
Mostafa Abdalla ◽  
Mary Frecker ◽  
Zafer Gürdal ◽  
Terrence Johnson ◽  
Douglas K Lindner
Keyword(s):  
Energy Efficiency ◽  
Piezoelectric Actuator ◽  
Compliant Mechanism ◽  
Maximum Energy

scholarly journals Topology optimization of steering knuckle structure

2020 ◽  
Vol 11 ◽  
pp. 4
Author(s):  
Saurabh Srivastava ◽  
Sachin Salunkhe ◽  
Sarang Pande ◽  
Bhavin Kapadiya
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Topology Optimization ◽  
Computer Aided Design ◽  
Research Work ◽  
Weight Ratio ◽  
Primary Objective ◽  
Second Phase ◽  
Structural Topology ◽  
Element Analysis

Steering knuckle connects steering system, suspension system and braking system to the chassis. The steering knuckle contributes a significant weight to the total weight of a vehicle. Increasing the efficiency of an automobile without compromising the performances is the major challenge faced by the manufacturers. This paper presents an effective topology optimization of steering knuckle used in a vehicle with the primary objective of minimizing weight. The study on optimization of knuckle is divided into two phases, the first phase involves making of a computer-aided design model of the original steering knuckle and carry out finite element analysis on the knuckle by estimating the loads, which are acting on the component. In the second phase, design optimization of the model of steering knuckle is carried out, and excess material is removed at the region where induced stress is negligible as obtained in finite element analysis assuming standard boundary and loading conditions. The paper describes a research work carried out to optimize structural topology giving the essential details. The methodology may be applied to optimize structural components used in applications where the ratio of desired properties to the cost, generally in terms of weight, is to be optimized. In the case of automobiles, strength to weight ratio has to be maximized. New researchers working in the area will have an understanding of the procedures, and further, the techniques may be applied to design in general.

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