Yingjun Wang^1,*, Zhenpei Wang^2,*, Zhaohui Xia³, Leong Hien Poh²

CMES-Computer Modeling in Engineering & Sciences, Vol.117, No.3, pp. 455-507, 2018, DOI:10.31614/cmes.2018.04603

Abstract Isogeometric analysis (IGA), an approach that integrates CAE into conventional CAD design tools, has been used in structural optimization for 10 years, with plenty of excellent research results. This paper provides a comprehensive review on isogeometric shape and topology optimization, with a brief coverage of size optimization. For isogeometric shape optimization, attention is focused on the parametrization methods, mesh updating schemes and shape sensitivity analyses. Some interesting observations, e.g. the popularity of using direct (differential) method for shape sensitivity analysis and the possibility of developing a large scale, seamlessly integrated analysis-design platform, are discussed in More >

Tongfa Deng^1,2, Junping Zhang^1,3,*, Mahmoud Bayat⁴

Structural Durability & Health Monitoring, Vol.12, No.3, pp. 189-212, 2018, DOI:10.3970/sdhm.2018.04392

Abstract The isolated curved girder bridge's vibration characteristics play a major part in the seismic responses of structures and anti-seismic properties. A clear analytic relationship between design parameters and the system's vibration characteristics could be established by its simplified dynamic analysis model, making it convenient for providing a reference to the optimization of design and safety analysis. A double-mass six-degree-of-freedom model for curved girder bridges with isolation bearings installed at the top of the bridge piers is built and a simplified analysis method for the vibration characteristics of the system is provided. Combined with the Matlab… More >

Marco Götz^1,*, Ferenc Leichsenring¹, Thomas Kropp², Peter Müller², Tobias Falk², Wolfgang Graf¹, Michael Kaliske¹, Welf-Guntram Drossel²

CMES-Computer Modeling in Engineering & Sciences, Vol.117, No.3, pp. 387-423, 2018, DOI:10.31614/cmes.2018.04112

Abstract Numerical mechanical models used for design of structures and processes are very complex and high-dimensionally parametrised. The understanding of the model characteristics is of interest for engineering tasks and subsequently for an efficient design. Multiple analysis methods are known and available to gain insight into existing models. In this contribution, selected methods from various fields are applied to a real world mechanical engineering example of a currently developed clinching process. The selection of introduced methods comprises techniques of machine learning and data mining, in which the utilization is aiming at a decreased numerical effort. The More >

L.L. Chen¹, H.B. Chen^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.107, No.3, pp. 249-276, 2015, DOI:10.3970/cmes.2015.107.249

Abstract Engineers have started to develop ways to decrease noise radiation. Structural-acoustic design sensitivity analysis can provide information on how changes in design variable affect the radiated acoustic performance. As such, it is an important step in the structural-acoustic design and in optimization processes. For thin structures immersed in water, a full interaction between the structural domain and the fluid domain needs to be taken into account. In this work, the finite element method is used to model the structure parts and the boundary element method is applied to the exterior acoustic problem. The formula of More >

T. Lahmer¹, J. Ilg², R. Lerch²

CMES-Computer Modeling in Engineering & Sciences, Vol.106, No.2, pp. 105-126, 2015, DOI:10.3970/cmes.2015.106.105

Abstract In the recent years many publications appeared putting emphasis on the simulation-based identification of piezoelectric material parameters from electrical or mechanical measurements and combinations of them. By experience, one is aware of the importance of a single input parameter. However, it is not yet fully understood and in particular quantified to which extend missing knowledge in the single parameters (parameter uncertainty) influences the quality of the model's prognosis. In this paper, we adapt and apply variance-based sensitivity measures to models describing the piezoelectric effect in the linear case and derive global information about the single More >

Marek Jasiński^*

Molecular & Cellular Biomechanics, Vol.10, No.3, pp. 183-199, 2013, DOI:10.3970/mcb.2013.010.183

Abstract In the paper the numerical analysis of thermal processes proceeding in the biological tissue is presented. The tissue is subjected to the external heat flux and 2D problem is taken into account. In order to determine the influence of variations of thermophysical parameters of tissue on the value of Arrhenius injury integral the direct approach of sensitivity analysis is applied. On the basis of tissue damage fraction the thermal injury formation process is analysed. At the stage of numerical realization the boundary element method is used. In the final part of the paper the example More >

L.L. Chen¹, H.B. Chen², C.J. Zheng³

CMES-Computer Modeling in Engineering & Sciences, Vol.94, No.6, pp. 459-483, 2013, DOI:10.3970/cmes.2013.094.459

Abstract A coupling algorithm based on the finite element method and the wideband fast multipole boundary element method (FEM/wideband FMBEM) is proposed for the simulation of fluid-structure interaction and structural-acoustic sensitivity analysis using the direct differentiation method. The wideband fast multipole method (FMM) formed by combining the original FMM and the diagonal form FMM is used to accelerate the matrix-vector products in the boundary element analysis. The iterative solver GMRES is applied to accelerate the solution of the linear system of equations. The FEM/Wideband FMBEM algorithm makes it possible to predict the effects of arbitrarily shaped More >

Marcin Kamiński^1,2, Bernd Lauke²

CMES-Computer Modeling in Engineering & Sciences, Vol.93, No.6, pp. 411-440, 2013, DOI:10.3970/cmes.2013.093.411

Abstract The main aim in this paper is a computational study devoted to the sensitivity gradients and probabilistic moments of the effective elastic parameters for the rubber-filled polymers. The methodology is based on least squares recovery of the polynomial functions relating the effective tensor components and the given input design/random parameters. All numerical experiments are provided with respect to Young’s moduli of the elastomer constituents. Computational analysis is possible thanks to the application of the Response Function Method, which is enriched in our approach with the weighting procedures implemented according to the Dirac-type distributions. The homogenized… More >

Christian Rauch^*

Frontiers in Heat and Mass Transfer, Vol.2, No.3, pp. 1-8, 2011, DOI:10.5098/hmt.v2.3.3006

Abstract In recent years, significant effort has been placed into developing automated multi-physics simulation. The exchange of boundary conditions has lead to more realistic as well as more complex simulations with usually slower convergence rate when the coupling is being performed between two different codes. In this paper the equations of local sensitivities for element centered steady-state combined convection, conduction, and thermal radiation problems are being derived. A numerical analysis on the stability of the solution matrix is being conducted. Partial uncertainties and the relative importance of the heat transfer modes are investigated by their uncertainty More >

C. J. ZHENG, H. B. CHEN, T. MATSUMOTO, T. TAKAHASHI

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.4, pp. 121-122, 2011, DOI:10.3970/icces.2011.019.121

Abstract A fast multipole boundary element method is presented for three dimensional acoustic shape sensitivity analysis in this study. The Burton-Miller formula which is a linear combination of the conventional boundary integral equation and the normal derivative boundary integral equation is adopted to conquer the fictitious eigenfrequency problem associated with the conventional boundary integral equation method in solving exterior acoustic problems. The continuous adjoint variable method is implemented in the sensitivity analysis and the concept of material derivative is used in the derivation. Constant elements are employed to discretize the boundary so that the hypersingular boundary More >