Jinhe Zhang², Jie Liu^1,2,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.4, pp. 1-2, 2023, DOI:10.32604/icces.2023.09279

Abstract The small uncertainties of geometric parameters of industrial robot, which are caused by links manufacturing and service wear errors, can deteriorate the positioning accuracy of end-effector through multi-level propagation and is difficult to be measured and compensated by high-precision instruments. Hence, an efficient inverse identification method of parameter uncertainty based on global sensitivity analysis and optimal measurement point selection is proposed. In order to ensure the universality of identification results in calibration and control works, the standard Denavit-Hartenberg (D-H) method is employed to establish the kinematic model of series 6 degrees of freedom (DOF) robots. Considering the stochastic error between… More >

R. Rajaraman^a , L. Anna Gowsalya^b,*, R. Velraj^c

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-8, 2018, DOI:10.5098/hmt.11.23

Abstract To get accurate results in casting simulations, prediction of interfacial heat transfer coefficient (IHTC) is imperative. In this paper an attempt has been made for estimating IHTC during solidification process of a rectangular aluminium alloy casting in a sand mould. The cast temperature and mould temperature are measured during the experimental process at different time intervals during the process of solidification. Two different inverse methods, namely control volume and Beck’s approach are used to estimate the heat flux and temperature at the mould surface by using the experimentally measured temperatures. In the case of control volume technique, the partial derivative… More >

Rui Chen^{1, 2}, Yong Wang^{1, 2}, Ruitao Peng^{1, 2, *}, Shengqiang Jiang^{1, 2}, Congfang Hu^{1, 2}, Ziheng Zhao^{1, 2}

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 717-737, 2020, DOI:10.32604/cmes.2020.07438

Abstract An inverse method for parameters identification of discrete element model combined with experiment is proposed. The inverse problem of parameter identification is transmitted to solve an optimization problem by minimizing the distance between the numerical calculations and experiment responses. In this method, the discrete element method is employed as numerical calculator for the forward problem. Then, the orthogonal experiment design with range analysis was used to carry out parameters sensitivity analysis. In addition, to improve the computational efficiency, the approximate model technique is used to replace the actual computational model. The intergeneration projection genetic algorithm (IP-GA) is employed as the… More >

Minliang Liu¹, Liang Liang², Xiaoying Lou³, Glen Iannucci³, Edward Chen³, Bradley Leshnower³, Wei Sun^1,*

Molecular & Cellular Biomechanics, Vol.16, Suppl.2, pp. 53-53, 2019, DOI:10.32604/mcb.2019.07387

Abstract It is well known that mechanical properties of the aortic wall exhibit patient-specific variations. Recent experimental findings also suggest the aortic wall properties are highly region-specific [1-2]. Thus, in vivo heterogeneous (non-uniform) nonlinear mechanical properties of the aortic wall of individual patients needs to be noninvasively identified for accurate prediction of clinical events (e.g. aortic rupture).
In this study, we developed an inverse approach for identification of patient-specific non-uniform material properties of the aortic wall from gated 3D CT scans. This inverse approach leverages the fact that the in vivo transmural mean stress (tension) of the aortic wall is… More >

Yue Mei^1,2,3, Stephane Avril^3,*

Molecular & Cellular Biomechanics, Vol.16, Suppl.2, pp. 44-44, 2019, DOI:10.32604/mcb.2019.07034

Abstract Characterizing regional variations of material properties in soft tissues is essential for biomedical engineering and clinical medicine, including but not limited to cancerous disease detection and patient-specific surgical planning of cardiovascular diseases. Identification of nonhomogeneous material property distribution usually requires solving inverse problems in nonlinear elasticity. Generally, inverse algorithms can be categorized into two groups: iterative inversion and direct inversion. In direct inversion, the material property distribution of soft tissues is estimated directly from the equilibrium equations, while the inverse problem is posed as an optimization problem in iterative inversion. In this presentation, we compare the performance of one direct… More >

J. C. Páscoa¹, A. C. Mendes¹, L. M. C. Gato², R. Elder³

CMES-Computer Modeling in Engineering & Sciences, Vol.6, No.6, pp. 537-546, 2004, DOI:10.3970/cmes.2004.006.537

Abstract The paper presents an aerodynamic design method for turbomachinery cascades of blades. The prescribed conditions are the aerodynamic blade load and the blade thickness distributions. An iterative procedure was implemented, based on the solution of the Euler equations, to seek the blade geometry that provides the specified design conditions. A central finite-volume explicit time-marching scheme is used to solve the Euler equations in two-dimensional flow. The numerical scheme uses an adaptive nonlinear artificial dissipation term based on the limiter theory. Starting with the results from the flow analysis through an initially guessed cascade geometry, the design code modifies the blade… More >

Hu Wang¹, Weiyi Li¹, Guangyao Li¹

CMC-Computers, Materials & Continua, Vol.28, No.2, pp. 121-146, 2012, DOI:10.3970/cmc.2012.028.121

Abstract The purpose of this study is to propose a robust inverse method for estimating Johnson-Cook material parameters. The method is shown through illustrative examples for two different advanced high strength steel (AHSS) materials (DP980 and TRIP780) using set of data from impact experiments with different velocities. Compared with widely mixed numerical experimental methods, the suggested inverse method has the capability to guarantee the robustness of the obtained parameters by considering uncertainties. The inverse problem is converted into multi-objective optimization problems. Furthermore, in order to improve the performance in efficiency and accuracy, metamodeling techniques and global optimization method are integrated. The… More >

Shen Shang and Gun Jin Yun^1,1

CMC-Computers, Materials & Continua, Vol.27, No.1, pp. 55-72, 2012, DOI:10.3970/cmc.2012.027.055

Abstract In this paper, the Self-Optimizing Inverse Method (Self-OPTIM) has been experimentally verified by identifying constitutive parameters solely based on prescribed boundary loadings without full-field displacements. Recently the Self-OPTIM methodology was developed as a computational inverse analysis tool that can identify parameters of nonlinear material constitutive models. However, the methodology was demonstrated only by numerically simulated testing with full-field displacement fields and prescribed boundary loadings. The Self-OPTIM is capable of identifying parameters of the chosen class of material constitutive models through minimization of an implicit objective function defined as a function of full-field stress and strain fields in the optimization process.… More >

M.R. Hematiyan^1,2, A. Khosravifard¹, Y.C. Shiah³, C.L. Tan⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.87, No.1, pp. 55-76, 2012, DOI:10.3970/cmes.2012.087.055

Abstract An inverse technique, based on the boundary element method (BEM) and elastostatic experiments for identification of elastic constants of orthotropic and general anisotropic 2D bodies is presented. Displacement measurements at several points on the boundary of the body, obtained by a few known load cases are used in the inverse analysis to find the unknown elastic constants of the body. Using data from more than one elastostatic experiment results in a more accurate and stable solution for the identification problem. In the inverse analysis, sensitivities of displacements of only boundary points with respect to the elastic constants are needed. Therefore,… More >