Design and Optimization of Thermomechanical Actuator via Contour Shaping

Author(s):  
Shih-Chi Chen ◽  
Martin L. Culpepper

In this paper we disclose how to contour the beams of micro-scale thermomechanical actuators (TMAs) in order to enhance the actuator’s thermal and mechanical performance. In this approach, we vary the cross section of the driving Joule heated beams over the length of the beam. Using this approach, (1) the stored mechanical energy and axial stiffness of beam may be modified to achieve an optimized force-displacement relationship, (2) the maximum achievable thermal strain of a driving beam may be increased by 29%, (3) actuator stroke may be increased by a factor of 3 or more, (4) identical force or displacement characteristics may be achieved with 90% reduction in power. This paper presents the theory and models used to predict the thermal and mechanical behavior of the actuator. The theory and models were used to create a deterministic link between the actuator’s design parameters and the actuator’s performance characteristics. The theory and models were combined within a design tool that shows less than 5% error from non-linear Finite Element Analysis simulations. The design tool has been used to generate plots that enable designers to (1) understand the qualitative relationships between design parameters and performance and (2) select first-pass design parameters. The theory was used to create a design tool, posted at http://psdam.mit.edu, that may be used to perform qualitative design assessment and optimization.

2011 ◽  
Vol 8 (3) ◽  
pp. 102-109
Author(s):  
K.B. Puneeth ◽  
K.N. Seetharamu

A predictive model of thermal actuator behavior has been developed and validated that can be used as a design tool to customize the performance of an actuator to a specific application. Modeling thermal actuator behavior requires the use of two sequentially or directly coupled models, the first to predict the temperature increase of the actuator due to the applied voltage and the second to model the mechanical response of the structure due to the increase in temperature. These models have been developed using ANSYS for both thermal response and structural response. Consolidation of FEA (finite element analysis) results has been carried out using an ANN (artificial neural network) in MATLAB. It is seen that an ANN can be successfully employed to interpolate and predict FEA results, thus avoiding necessity of running FEA code for every new case. Furtheroptimization of geometry for maximum actuation length has been carried out using a GA (genetic algorithm) in MATLAB. The results of the GA were verified against the ANN and FEA results.


Volume 4 ◽  
2004 ◽  
Author(s):  
Hamid A. Hadim ◽  
Tohru Suwa

A new multidisciplinary design and optimization methodology in electronics packaging is presented. A genetic algorithm combined with multi-disciplinary design and multi-physics analysis tools are used to optimize key design parameters. This methodology is developed to improve the electronic package design process by performing multidisciplinary design and optimization at an early design stage. To demonstrate its capability, the methodology is applied to a Ball Grid Array (BGA) package design. Multidisciplinary criteria including thermal, thermal strain, electromagnetic leakage, and cost are optimized simultaneously. A simplified routability analysis criterion is treated as a constraint. The genetic algorithm is used for systematic design optimization while reducing the total computational time. The present methodology can be applied to any electronics product design at any packaging level from the chip level to the system level.


2012 ◽  
Vol 215-216 ◽  
pp. 847-850
Author(s):  
Shou Jun Wang ◽  
Xing Xiong ◽  
Hong Jie Wang

In the condition of alternating impact ,the nut-supports subassembly is analyzed according to uncertainty of design parameters. Firstly, a three-dimensional (3-D) finite element (FE) model of the nut-supports subassembly is built and is meshed,and the constraints and loads are imposed.Secondly,the model of nut-supports was assembled using the software ANSYS to understand the stress distribution and various parts of the deformation of the nut-supports and its weak links in the harmonic forces.Finally,socket head cap screw has not enough pre-load in the condition of alternating impact and will be simplified.It is analyzed and checked whether it is cut or not; which provides the reference data for design and optimization of the wave maker.


Author(s):  
Nic Debusschere ◽  
Matthieu De Beule ◽  
Peter Dubruel ◽  
Patrick Segers ◽  
Benedict Verhegghe

Biodegradable stents, which temporarily support a stenotic blood vessel and afterwards fully disappear, have recently gained a lot of interest. They avoid long-term complications associated with conventional stents such as late stent thrombosis and in-stent restenosis. Moreover, degradable stents allow for a restoration of vasomotion and vessel growth which makes them particularly suitable for pediatric applications [1]. Finite element simulations have proven to be an efficient and cost-effective tool to investigate and optimize the mechanical performance of minimal invasive devices such as stents [2]. Biodegradable stents have however created new challenges in their design and optimization via finite element analysis because of their complex time-varying material behavior. To correctly simulate the mechanical behavior of biodegradable stents, a model should be developed that incorporates the effect of degradation upon all material characteristics. By combining existing constitutive material models based on continuum damage theory we were able to create such a virtual environment in which the transitional mechanical behavior of biodegradable stents can be investigated.


2003 ◽  
Author(s):  
Hamid Hadim ◽  
Tohru Suwa

In this manuscript a systematic multidisciplinary electronic packaging design and optimization methodology based on the artificial neural networks technique is presented. This method is applied to a Ball Grid Array (BGA) package design as an example. Multidisciplinary criteria including thermal, structural (thermal strain), electromagnetic leakage, and cost are optimized simultaneously. A simplified routability criterion is also considered as a constraint. The artificial neural networks technique is used for thermal and structural performance predictions. Large calculation time reduction is achieved using the artificial neural networks, which also provide enough information to specify the individual weights for each design discipline within the objective function used for optimization. This methodology is able to provide the designers a clear view of the design trade-offs, which are represented in the objective function using various design parameters. This methodology can be applied to any electronic product design at any packaging level.


Author(s):  
Shaopeng Wang ◽  
Jinguang Ma ◽  
Chengcheng Liu ◽  
Youhua Wang ◽  
Gang Lei ◽  
...  

This paper proposes a novel permanent magnet assisted synchronous reluctance (PMAREL) machine, the main structure of this machine is quite similar to that of traditional PMAREL machine, and the main difference is that the grain-oriented silicon steel is used to replace some part of the stator teeth. The rolling direction of the grain-oriented silicon steel is along the radial direction of the machine, thus the advantage of higher permeability and higher kneel point in this material can be used to release the flux saturation problem of the traditional non-grain-oriented steel used in the PMAREL machine when the applied current density is high. Firstly, the structure of both proposed novel and traditional PMAREL machines are optimized and the design parameters are determined. Secondly the electromagnetic and mechanical performance are compared in these two machines which includes the demagnetization analysis, mechanical stress analysis when the rotor at the maximum speed, torque ability, efficiency by using the finite element method (FEM). It can be seen that the problem of stator teeth saturation in the novel PMAREL has been alleviated, and compared with the traditional PMAREL machine, the novel PMAREL has higher efficiency, wider speed range and 7% higher torque ability.


2013 ◽  
Vol 427-429 ◽  
pp. 90-93 ◽  
Author(s):  
Wen Qing Wang

Based on the principle of orthogonal test, the optimization model of sunflower shaped arch bridge scheme was set up. The five key design parameters were selected as the main factors. The four computation index, which reflect mechanical performance, were selected as analytical objects. The 16 orthogonal experiment schemes were arranged with four levels orthogonal table . The curves of the factors to the index were obtained from the mechanical response under dead load and live load through the finite element analysis model. By the range analysis method, the influential levels of the factors to the index were obtained from the result of the test , and the factor optimizatuion level of the factors was determined to further optimize the layout scheme of the sunfloawer shaped arch bridge.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Jiaming Hu ◽  
Junyi Wang ◽  
Yu Xie ◽  
Chenzhi Shi ◽  
Yun Chen

Since proposed, the perforated honeycomb-corrugation sandwich panel has attracted a lot of attention due to its superior broadband sound absorption at low frequencies and excellent mechanical stiffness/strength. However, most existing studies have assumed a structure made of high-strength materials and studied its performance based on the ideal rigid-wall model with little consideration for acoustic-structure interaction, thereby neglecting the structural vibrations caused by the material’s elasticity. In this paper, we developed a more realistic model considering the solid structural dynamics using the finite element method (FEM) and by applying aluminum and rubber as the structural material. The enhancement of the low-frequency performance and inhibition of broadband absorption coexisted in low-strength rubbers, implying a compromise in the selection of Young's modulus to balance these two influences. Further analysis on thermal-viscous dissipation, mechanical energy, and average structural stress indicated that the structure should work right below the resonant frequency for optimization. Based on these findings, we designed a novel aluminum-rubber composite structure possessing enhanced low-frequency absorption, high resistance to shear load, normal compression, and thermal expansion. Our research is expected to shed some light on noise control and the design of multifunctional acoustic metamaterials.


The crankshaft is a compact revolving element present in IC engines that transform the rectilinear motion of the piston into continuous rotary motion. The proper design and assembly of the crankshaft can ensure the smooth conversion of mechanical energy from reciprocating pistons to the drive system. The power dissipation, energy losses, noise, and vibration that are produced during operation directly affects the efficiency of the vehicle. The existing design of the crankshaft is a track-proven model for many decades. The manufacturing process of this involved large number of machining operation. Even though, during the long course of application, the crankshaft assembly produces some noise, vibration that leads to discomfort in ride and sharp fall in mileage of the vehicle that reduces efficiency. In order to overcome these problems, the design modification is done to improve the life and performance of the crankshaft assembly. A detailed study and analysis of the existing model are undertaken. Based on the experimental and analytical reviews; suitable design modification is made to suit the compact assembly in place of existing high weight and large crankshaft assembly. In the present work, design modification and numerical investigation of a crankshaft assembly is carried out. This crankshaft assembly is used mainly in a single cylinder, four strokes internal combustion engine. The stress comparison study is carried out between the existing design and the modified design by doing finite element analysis. The result shows that the modified design exhibits better performance and low stress than the existing model.


Author(s):  
Paul F. Egan ◽  
Philip R. LeDuc ◽  
Jonathan Cagan ◽  
Christian Schunn

As technology advances, there is an increasing need to reliably output mechanical work at smaller scales. At the nanoscale, one of the most promising routes is utilizing biomolecular motors such as myosin proteins commonly found in cells. Myosins convert chemical energy into mechanical energy and are strong candidates for use as components of artificial nanodevices and multi-scale systems. Isoforms of the myosin superfamily of proteins are fine-tuned for specific cellular tasks such as intracellular transport, cell division, and muscle contraction. The modular structure that all myosins share makes it possible to genetically engineer them for fine-tuned performance in specific applications. In this study, a parametric analysis is conducted in order to explore the design space of Myosin II isoforms. The crossbridge model for myosin mechanics is used as a basis for a parametric study. The study sweeps commonly manipulated myosin performance variables and explores novel ways of tuning their performance. The analysis demonstrates the extent that myosin designs are alterable. Additionally, the study informs the biological community of gaps in experimentally tabulated myosin design parameters. The study lays the foundation for further progressing the design and optimization of individual myosins, a pivotal step in the eventual utilization of custom-built biomotors for a broad range of innovative nanotechnological devices.


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