Jinlan Xu^*, Ningning Sun, Gang Xu

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.2, pp. 627-642, 2020, DOI:10.32604/cmes.2020.010341 - 20 July 2020

Abstract This paper presents a novel approximating method to construct highprecision single-patch representation of B-spline surface from a multi-patch representation for isogeometric applications. In isogeometric analysis, multi-patch structure is not easy to achieve high continuity between neighboring patches which will reduce the advantage of isogeometric analysis in a sense. The proposed method can achieve high continuity at surface stitching region with low geometric error, and this technique exploits constructing the approximate surface with several control points are from original surfaces, which guarantees the local feature of the surface can be well-preserved with high precision. With the More >

Yang Xia^*, Luting Deng, Jian Zhao

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.2, pp. 605-626, 2020, DOI:10.32604/cmes.2020.010204 - 20 July 2020

Abstract Geometric fitting based on discrete points to establish curve structures is an important problem in numerical modeling. The purpose of this paper is to investigate the geometric fitting method for curved beam structure from points, and to get high-quality parametric model for isogeometric analysis. A Timoshenko beam element is established for an initially curved spacial beam with arbitrary curvature. The approximation and interpolation methods to get parametric models of curves from given points are examined, and three strategies of parameterization, meaning the equally spaced method, the chord length method and the centripetal method are considered.… More >

Shige Wang¹, Zhongwang Wang¹, Leilei Chen¹, Haojie Lian^2,3,*, Xuan Peng⁴, Haibo Chen⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.2, pp. 585-604, 2020, DOI:10.32604/cmes.2020.09904 - 20 July 2020

Abstract The paper applied the isogeometric boundary element method (IGABEM) to thermoelastic problems. The Non-Uniform Rational B-splines (NURBS) used to construct geometric models are employed to discretize the boundary integral formulation of the governing equation. Due to the existence of thermal stress, the domain integral term appears in the boundary integral equation. We resolve this problem by incorporating radial integration method into IGABEM which converts the domain integral to the boundary integral. In this way, IGABEM can maintain its advantages in dimensionality reduction and more importantly, seamless integration of CAD and numerical analysis based on boundary More >

Xiaozhong Chen^*

Molecular & Cellular Biomechanics, Vol.17, No.3, pp. 139-153, 2020, DOI:10.32604/mcb.2020.08933 - 01 July 2020

Abstract Existing model registration of individual bones does not have a high certainly of success due to the lack of anatomic semantic. In light of the surface anatomy and functional structure of bones, we hypothesized individual femur models would be aligned through feature points both in geometrical level and in anatomic level, and proposed a hierarchical approach for the rigid registration (HRR) of point cloud models of femur with high resolution. Firstly, a coarse registration between two simplified point cloud models was implemented based on the extraction of geometric feature points (GFPs); and then, according to More >

Long Chen¹, Li Xu¹, Kai Wang¹, Baotong Li^2,*, Jun Hong²

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.1, pp. 203-225, 2020, DOI:10.32604/cmes.2020.09896 - 19 June 2020

Abstract The geometric model and the analysis model can be unified together through the isogeometric analysis method, which has potential to achieve seamless integration of CAD and CAE. Parametric design is a mainstream and successful method in CAD field. This method is not continued in simulation and optimization stage because of the model conversion in conventional optimization method based on the finite element analysis. So integration of the parametric modeling and the structural optimization by using isogeometric analysis is a natural and interesting issue. This paper proposed a method to realize a structural optimization of parametric… More >

Chao Mei, Qifu Wang^*, Chen Yu, Zhaohui Xia

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.1, pp. 179-202, 2020, DOI:10.32604/cmes.2020.09948 - 19 June 2020

Abstract This paper presents a topology optimization method for variable stiffness composite panels with varying fiber orientation and curvilinear fiber path. Non-uniform rational B-Splines (NURBS) based Isogeometric analysis (IGA) is utilized for the numerical computation of the general minimum compliance problem. The sensitivity analysis of the structure compliance function for the density and bi-layer orientation is conducted. The bi-layer fiber paths in the design domain are generated using streamline method and updated by divided pieces reselection method after the optimization process. Several common examples are tested to demonstrate the effectiveness of the method. The results show More >

Jin Han¹, Wenhao Jiang¹, Jin Shi^{2, *}, Sun Xin², Jin Peng², Haibo Liu³

CMC-Computers, Materials & Continua, Vol.64, No.2, pp. 1171-1184, 2020, DOI:10.32604/cmc.2019.07447 - 10 June 2020

Abstract The assessment of the fairness of health resource allocation is an important part of the study for the fairness of social development. The data used in most of the existing assessment methods comes from statistical yearbooks or field survey sampling. These statistics are generally based on administrative areas and are difficult to support a fine-grained evaluation model. In response to these problems, the evaluation method proposed in this paper is based on the query statistics of the geographic grid of the target area, which are more accurate and efficient. Based on the query statistics of… More >

Gang Zhao^1,2, Jiaming Yang¹, Wei Wang^1,*, Yang Zhang¹, Xiaoxiao Du¹, Mayi Guo¹

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.3, pp. 1033-1059, 2020, DOI:10.32604/cmes.2020.09920 - 28 May 2020

Abstract In this paper, a new isogeometric topology optimization (ITO) method is proposed by using T-splines based isogeometric analysis (IGA). The arbitrarily shaped design domains, directly obtained from CAD, are represented by a single T-spline surface which overcomes the topological limitations of Non-Uniform Rational B-Spline (NURBS). The coefficients correlated with control points are directly used as design variables. Therefore, the T-spline basis functions applied for geometry description and calculation of structural response are simultaneously introduced to represent the density distribution. Several numerical examples show that the proposed approach leads to a coherent workflow to handle design More >

Zelong Wang^{1, 2, 3, *}, Xiangui Liu^{1, 2, 3}, Haifa Tang³, Zhikai Lv³, Qunming Liu³

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 873-893, 2020, DOI:10.32604/cmes.2020.08993 - 01 May 2020

Abstract The Ensemble Kalman Filter (EnKF), as the most popular sequential data assimilation algorithm for history matching, has the intrinsic problem of high computational cost and the potential inconsistency of state variables updated at each loop of data assimilation and its corresponding reservoir simulated result. This problem forbids the reservoir engineers to make the best use of the 4D seismic data, which provides valuable information about the fluid change inside the reservoir. Moreover, only matching the production data in the past is not enough to accurately forecast the future, and the development plan based on the… More >

Mayi Guo, Gang Zhao, Wei Wang^*, Xiaoxiao Du, Ran Zhang, Jiaming Yang

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 821-843, 2020, DOI:10.32604/cmes.2020.09898 - 01 May 2020

Abstract Nonlinear behaviors are commonplace in many complex engineering applications, e.g., metal forming, vehicle crash test and so on. This paper focuses on the T-spline based isogeometric analysis of two-dimensional nonlinear problems including general large deformation hyperelastic problems and small deformation elastoplastic problems, to reveal the advantages of local refinement property of T-splines in describing nonlinear behavior of materials. By applying the adaptive refinement capability of T-splines during the iteration process of analysis, the numerical simulation accuracy of the nonlinear model could be increased dramatically. The Bézier extraction of the T-splines provides an element structure for More >