The Finite Element Model (FEM) Updating of Mirror Frame System Based on Response Surface Method

2011 ◽  
Vol 291-294 ◽  
pp. 1615-1620
Author(s):  
Xue Qian Chen ◽  
Shi Fu Xiao ◽  
Xin En Liu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Response Surface ◽  
Response Surface Method ◽  
Element Model ◽  
Surface Model ◽  
Surface Method ◽  
Frame System ◽  
Relative Errors ◽  
The Finite Element Model

It is difficult in finite element model(FEM) updating, because the essence is a mechanical anti-question solving. In the paper, the suppositional material method is utilized to model the FEM of a mirror frame system, and the required updating parameters are defined. The functions between the natural frequency and the updating parameters are established based on the response surface method. Based on the response surface model and the modal experiment results, the sum of absolute value of relative errors between the results of experiments and simulations is defined as the optimization objective, four required updating are identified automatically. The first three natural frequencies of updated mirror frame system are better accordant with the experiment results, which proves the method correct and reliable.

Static and Dynamic Finite Element Model Updating of a Rigid Frame-Continuous Girders Bridge Based on Response Surface Method

2013 ◽  
Vol 639-640 ◽  
pp. 992-997 ◽  
Author(s):  
Jian Ping Han ◽  
Yong Peng Luo
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Response Surface ◽  
Test Data ◽  
Dynamic Test ◽  
Element Model ◽  
Surface Method ◽  
Rigid Frame ◽  
The Finite Element Model

Using the static and dynamic test data simultaneously to update the finite element model can increase the available information for updating. It can overcome the disadvantages of updating based on static or dynamic test data only. In this paper, the response surface method is adopted to update the finite element model of the structure based on the static and dynamic test. Using the reasonable experiment design and regression techniques, a response surface model is formulated to approximate the relationships between the parameters and response values instead of the initial finite element model for further updating. First, a numerical example of a reinforced concrete simply supported beam is used to demonstrate the feasibility of this approach. Then, this approach is applied to update the finite element model of a prestressed reinforced concrete rigid frame-continuous girders bridge based on in-situ static and dynamic test data. Results show that this approach works well and achieve reasonable physical explanations for the updated parameters. The results from the updated model are in good agreement with the results from the in-situ measurement. The updated finite element model can accurately represent mechanical properties of the bridge and it can serve as a benchmark model for further damage detection and condition assessment of the bridge.

scholarly journals Variable Stiffness Design and Multiobjective Crashworthiness Optimization for Collision Post of Subway Cab Cars

Machines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 246
Author(s):  
Wei Guo ◽  
Ping Xu ◽  
Zhaofeng Yi ◽  
Jie Xing ◽  
Hui Zhao ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Response Surface ◽  
Energy Absorption ◽  
Pareto Frontier ◽  
Variable Stiffness ◽  
Element Model ◽  
Surface Model ◽  
Front End ◽  
The Finite Element Model

This paper proposes a variable stiffness collision post (VSCP) structure based on a uniform stiffness collision post (USCP) structure and performs stiffness matching optimization for VSCPs. A collision post structure assembled in a subway front-end frame can maintain the living space and absorb a certain amount of the kinetic energy of an impact. The experiment was applied on USCP, and the finite element model was verified experimentally. To investigate the effects of the stiffness parameters of VSCP on the specific energy absorption response (SEA_VSCP) and the area of intrusion response (S_In), response surface models fitted from design of experiment were adopted with the finite element model. In addition, a multiobjective optimization design was realized by using the global response search method and a Pareto frontier sequence was generated, which was based on the developed response surface model. It was found that the optimal value of SEA_VSCP and S_In responses cannot be achieved at the same time. Finally, a grey relational analysis is propounded to attain a desirable balance between SEA_VSCP and S_In from the Pareto frontier sequence under constraints of the peak crash force of VSCP and energy absorption of the front-end of cab car. The optimization result shows that the crashworthiness of VSCP is better than that of USCP.

Static Finite Element Model Updating for Special-Shaped Bridge Based on Response Surface Method

2012 ◽  
Vol 236-237 ◽  
pp. 611-616
Author(s):  
Han Bing Liu ◽  
Yan Jun Song ◽  
Ya Feng Gong
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Response Surface ◽  
Response Surface Method ◽  
Model Updating ◽  
Design Method ◽  
Uniform Design ◽  
Element Model ◽  
Finite Element Software ◽  
Surface Method

The establishment of an effective finite element model for bridge structure is essential in the health monitoring system for Bridge. A new updating method for static model using response surface method is proposed in this paper, and the main procedures are given with an example of a special-shaped bridge. Firstly, the bridge deflection and strain data in designed load case are obtained. Several groups of combined parameters which are chosen based on the principle of uniform design method are selected to conduct calculation through finite element software. Finally through response surface fitting and optimization, the updated bridge finite element model is obtained. The results show that the updated model is approximate to the real bridge and this updating method is rational and practical.

An Efficient Method for Predicting Fracture of Hard Food Source

2008 ◽  
Author(s):  
Nirdesh D. Patel ◽  
Ian Grosse ◽  
Dan Sweeney ◽  
David S. Strait ◽  
Peter W. Lucas ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Food Item ◽  
Food Source ◽  
Element Model ◽  
Bite Force ◽  
Tooth Surface ◽  
Surface Model ◽  
Physical Testing ◽  
The Finite Element Model

In this paper we present a fast and reliable method for estimating the bite force required to fracture hard foods. The process involves complementary physical testing and finite element modeling. For physical testing, metal castings of upper or lower teeth are prepared. Metal tooth castings are mounted on a pivoting fixture interfaced to an Instron machine to simulate bite mechanics and thus to fracture hard food specimens. For the finite element model the tooth surfaces are modeled as rigid surface bodies in a nonlinear multi-load step contact analysis, while the food item is modeled as an elastic body. However, because only tooth surface information is needed in the model, we are able to automatically develop the geometry of the tooth surface using a tactile digitizing stylus with stereo lithographic surface profile information directly exported and subsequently imported into the FEA tool. We therefore avoid the need to laser scan tooth geometry which introduces significant “noise” into the surface model representation that must be painstakingly “cleaned” manually using software tools. The physical testing provides the force required to fracture the food item, while the finite element model provides the complete stress and strain state of the food item at the moment of fracture. Using this approach we have simulated the tooth biting mechanics of fossil primates to estimate biting force required to initiate a crack in a hard food source such as a macadamia nut. These analyses are designed to measure how occlusal morphology affects feeding performance, as the bite force needed to initiate a crack may vary according to tooth shape. The bite forces found using this approach will be used as an input for full-skull finite element models of early hominids (extinct fossil relatives of humans). The results of this work will be useful in testing the hypothesis that derived craniodental features in some of these hominids are adaptations for feeding on hard, brittle, seasonally available foods.

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