Dynamical Limit of Compliant Lever Mechanisms

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Michele Bonaldi ◽  
Mario Saraceni ◽  
Enrico Serra
Keyword(s):  
Finite Element ◽  
Multiobjective Optimization ◽  
Elastic Constants ◽  
Upper Bound ◽  
Strain Energy ◽  
Mechanical Energy ◽  
Element Model ◽  
Positive Definite ◽  
Optimization Analysis ◽  
Energy Conservation Principle

The application of the mechanical energy conservation principle sets a dynamical limit to the performances of compliant lever mechanisms endowed with a positive definite strain energy. The limit applies to every linear compliant lever and is given as an upper bound on the product between the static effective gain of the device and its bandwidth. The relevant parameters of this relation are determined only by the structures surrounding the device and not by its design. This result is obtained on the basis of a linear two-port model, with coefficients determined by the static elastic constants of the device. The model and the dynamical limit are validated by multiobjective optimization analysis interfaced with a finite element model of a practical mechanism.

Optimization Method of Hoisting Points Schemes Using Strain Energy Criterion

2011 ◽  
Vol 88-89 ◽  
pp. 583-586
Author(s):  
Shun Guo Li ◽  
Hui Li
Keyword(s):  
Finite Element ◽  
Strain Energy ◽  
Energy Criterion ◽  
Element Model ◽  
Optimization Method ◽  
Optimization Analysis ◽  
Element Analysis ◽  
Single Target ◽  
Steel Truss ◽  
Calculation Code

The optimization method of hoisting point’s schemes using strain energy criterion was studied in this paper. Firstly, the finite element model of complex steel truss hoisting was established and optimization analysis of hoisting point’s schemes for complex steel truss hoisting using strain energy criterion was accomplished. The calculation code which can make finite element analysis and optimization analysis of lifting point’s schemes based on strain energy criterion automatically. Then, lifting point’s schemes of complex steel truss hoisting were analyzed with calculation code mentioned above. The results indicate that, the optimization index using strain energy criterion is just strain energy criterion which is a more comprehensive and unidirectional index. Optimization analysis based on strain energy criterion changes optimization analysis of the lifting points schemes for complex steel truss hoisting from multi-target optimization into single-target optimization. The case study shows that this method is practicable and reliable and have good application prospect in hoisting points schemes optimization analysis with application to complex steel truss hoisting.

scholarly journals Influence of Dynamic Loading on Fracture Behaviour of DCB Sandwich Specimen

2019 ◽  
Vol 29 ◽  
pp. 02003 ◽  
Author(s):  
Vyacheslav N. Burlayenko ◽  
Tomasz Sadowski ◽  
Daniel Pietras
Keyword(s):  
Finite Element ◽  
Dynamic Fracture ◽  
Strain Energy ◽  
Fracture Behaviour ◽  
Sandwich Beam ◽  
Strain Energy Release ◽  
Element Model ◽  
Dynamic Finite Element ◽  
Sandwich Specimen ◽  
The Finite Element Model

Numerical simulations of dynamic fracture behaviour of a double cantilever sandwich beam subjected to uneven bending moments in plane conditions are carried out using the dynamic finite element analyses with the ABAQUSTM code. The strain energy release rate was evaluated by means of the finite element model developed within the two-dimensional (2-D) linear elastodynamic theory. This demonstrates the capability and the reliability of the finite element modelling as an extremely useful numerical tool for solving dynamic fracture mechanics problems. Also, the dynamic behaviour of fracture parameters and interface crack progression is discussed.

The Modal Analysis for the Separate Frame Construction of a SUV

2011 ◽  
Vol 130-134 ◽  
pp. 365-368
Author(s):  
Feng Huang ◽  
Li Juan Wang ◽  
Zong Yu Chen ◽  
Li Du
Keyword(s):  
Finite Element ◽  
Energy Distribution ◽  
Strain Energy ◽  
Vibration Mode ◽  
Dynamic Performance ◽  
Element Model ◽  
Body Structure ◽  
Modal Strain Energy ◽  
Frame Construction ◽  
The Finite Element Model

The market share for sport utility vehicles is becoming increasingly very fast in recent years. Many auto companies are stepping up the work of research and development the new model of SUV. A new SUV body modal is studied in this paper. The finite element model of the SUV frame is built by the HyperMesh and the SUV frame modal is researched by the Nastran. Low-order vibration mode and the first bending and torsion modal strain energy distribution of the SUV body structure are obtained, and the SUV body structure of the dynamic performance was assessed in this paper.

Multi-scale finite element modeling of bending behavior of 3D multi-cell spacer weft-knitted composites with different structures

2021 ◽  
pp. 096739112110467
Author(s):  
Can Yang ◽  
Ming Lu ◽  
Amir Reza Eskenati
Keyword(s):  
Finite Element ◽  
Elastic Constants ◽  
Bending Strength ◽  
Nonlinear Behavior ◽  
Element Model ◽  
Textile Composites ◽  
Multi Scale ◽  
Bending Load ◽  
Linear And Nonlinear ◽  
Meso Scale

In the present study, a multi-scale finite element model is proposed to predict the linear and nonlinear behavior of the 3D multi-cell spacer weft-knitted composite under bending load. In this study, a unit-cell of the composite which includes plain and biaxial weft-knitted structures was modeled at the meso scale. Periodic boundary conditions were applied to the meso model to calculate the elastic constants of each composite structure. In order to obtain failure parameters of the composites, the Puck failure criterion model was utilized by a VUMAT code for the meso model. Afterward, the elastic constants of the composites based on a Python code were extracted from the meso model. Moreover, failure parameters that include tensile and compressive strength through the fiber and transverse directions were obtained from the meso model. All elastic and failure parameters were used for the macro model which is created with different profiles under bending load. The numerical results at the meso scale showed that the presence of the weft and warp yarns inside the biaxial weft-knitted composite increases the strength of the composite through the course and wale directions. Moreover, the stiffness of the composite would be improved. So, the samples that contained a biaxial composite had more stiffness and bending strength in comparison with plain composite samples because the top and bottom layers were manufactured by the biaxial weft-knitted structure. Besides, the comparison between numerical and experimental force–deflection curves showed that the proposed model could predict the linear and nonlinear behavior of the composites with high accuracy. So, this model can be used for other textile composites with complex shapes to predict the mechanical behavior of them.

Measurement of the Large Strain Behaviour of Aircraft Tyre Rubber

2006 ◽  
Vol 3-4 ◽  
pp. 435-0
Author(s):  
Robert A.W. Mines ◽  
R.S. Birch ◽  
S. McKown ◽  
D. Karagiozova
Keyword(s):  
Mechanical Property ◽  
Finite Element ◽  
Strain Energy ◽  
Large Strain ◽  
Element Model ◽  
Tensile Tests ◽  
Constitutive Behaviour ◽  
Compression Tests ◽  
Strain Behaviour ◽  
Dynamic Tensile Tests

The paper describes mechanical property tests on a Concorde aircraft tyre rubber. The tyre rubber is taken from the tyre tread, and consists of nylon reinforcement, laid up in an angle ply form. The constitutive behaviour of the rubber is characterised using the Mooney Rivlin approach, in which deformation is expressed in terms of strain energy. Static and dynamic tensile tests are conducted along the major reinforcement and minor reinforcement axes in the plane of the tread, and compression tests are conducted through the tread thickness. This data is then input into a finite element model of the tyre, using DYNA.

Advanced finite element cross-country ski boot model for mass optimization directions considering flexion stiffness

2017 ◽  
Vol 232 (3) ◽  
pp. 264-274
Author(s):  
Jurij Hladnik ◽  
Boris Jerman
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Strain Energy ◽  
Element Model ◽  
High Mass ◽  
Model Accuracy ◽  
Cross Country Skiing ◽  
Cross Country ◽  
Front Region ◽  
The Finite Element Model

Flexion stiffness and mass were recognized as two important parameters of energy efficiency for modern top-class ski boots used in skate cross-country skiing. This article summarizes the study on mass optimization of the front foot region of an existing cross-country ski boot, while considering its flexion stiffness. For this purpose, a finite element model of the boot and an artificial foot for simulation of boot flexion stiffness measurement were made. The boot consists of textiles which require specific measurements for their characterization and special finite element material models for their realization. The finite element model was validated through a three-step validation process, in which flexion stiffness of the complete and stripped versions of the finite element model were compared with experimentally acquired flexion stiffness. Flexion stiffness contributions of individual boot components of the front foot region were acquired from the strain energy accumulated in their finite element. Using flexion stiffness and mass contributions and ratios between them (flexion stiffness to mass contributions), directions for flexion stiffness to mass contribution optimization of the boot’s front region were determined. The shoe-upper and shoe-cap were the most efficient regarding their flexion stiffness to mass contribution ratios and were suggested to be thickened. The soles had the highest potential for the boot’s flexion stiffness to mass contribution optimization due to their high mass contribution and relatively low flexion stiffness to mass contribution ratios. As a result, recommendations were made to reduce the soles’ size and/or increase their flexion stiffness to mass contribution ratios. These recommendations are similar to recommendations from a previous study, despite the higher finite element model accuracy and different method used to determine the flexion stiffness contributions.

Analysis on Spindle of 2MW Wind Generator

2011 ◽  
Vol 121-126 ◽  
pp. 2532-2536
Author(s):  
Jia Hong Zheng ◽  
Min Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Element Model ◽  
Optimal Model ◽  
Optimization Analysis ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
The Mathematical Model ◽  
The Finite Element Model ◽  
Complete Optimization

The model of the spindle was made while the related characteristics and parameters were analysising,and then it was inducted in ANSYS finite element analysis software. Through carrying the constraint on the finite element model, the spindle was completed to realize the finite element analysis. At last, the model was inducted in MATLAB to establish the optimal model, through the mathematical model ,it was realised to complete optimization analysis.

Body Structure Static-Dynamic Analysis and Optimization of a Commercial Vehicle

2014 ◽  
Vol 621 ◽  
pp. 400-406
Author(s):  
Ming Ming Wang ◽  
Teng Fei Li ◽  
Xin Li ◽  
Cheng Liu ◽  
Hui Xia Liu
Keyword(s):  
Finite Element ◽  
Strain Energy ◽  
Optimization Design ◽  
Lightweight Design ◽  
Element Model ◽  
Element Size ◽  
Design Variables ◽  
Wide Range ◽  
Static Performance

White body in the design process needs to meet the needs of a wide range of performance requirement. Adequate stiffness and modal are the basis to ensure the vehicle’s performance of vibration noise. Simultaneously, in order to reduce energy consumption and cost, the lightweight design of the white body has become the mainstream. In this paper, the optimization design is conducted for stiffness and modal of a commercial vehicle’s white body based on the theory of the finite element size sensitivity optimization design. Firstly, build the finite element model of a vehicle’s white body and analyze its stiffness and modal. Some changes were made to the car-body’s partial structure according to the distributing of strain energy achieved from above analysis, which improved the car-body’s dynamic and static performance initially. Secondly, choose panels needed to be optimized by reference to the density of strain energy and panels’ mass. Then, the car-body’s structure was optimized using panels’ thickness as design variables, stiffness and modal frequencies as constrains and minimizing weight of white car-body as objective. After the analysis of the result, modal separation was put forward to improve the quality of this finite element optimization design model. Finally, the car-body’s stiffness and mode nature entirely satisfied the requirements with car-body’s weight decreased.

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