Quansheng Zang

Bio: Quansheng Zang is an academic researcher from Dalian University of Technology. The author has contributed to research in topics: Finite element method & Boundary value problem. The author has an hindex of 5, co-authored 21 publications receiving 80 citations.

Investigation of bending behavior for laminated composite magneto-electro-elastic cylindrical shells subjected to mechanical or electric/magnetic loads

Abstract: Due to the multidisciplinary nature for the solution of magneto-electro-elastic (MEE) shell structures, developing a novel and accurate computational model is both essential and necessary for the practical engineering. The scaled boundary finite element method (SBFEM) is a semi-analytical technique in which only the surfaces or boundaries of the computational domain need to be discretized, while an analytical formulation can be derived in the radial direction of the surrounding area. These advanced features enable the spatial dimension to be reduced by one, while the accuracy of the proposed algorithm is maintained. In this paper, a novel semi-analytical numerical model based on the SBFEM is developed for the bending analysis of the laminated MEE cylindrical shells under the mechanical or electric/magnetic potential loads. According to the three-dimensional (3D) magneto-electro-elasticity theory, the magneto-electro-mechanical coupling equations and the associated boundary conditions in terms of the mechanical displacement as well as the electrical and magnetical potentials are derived in the scaled boundary coordinate system using the weighted-residual method. The analytical expressions for the generalized displacement and internal nodal force fields are determined by applying the state-space method and have been solved by means of the precise integration technique (PIT). Comparisons between the present numerical results for limiting conditions and solutions available in the published work have been carried out to demonstrate the convergence and accuracy of this approach. At the same time, by utilizing the proposed mechanics, the influences of the aspect ratio and stacking configuration on the through-thickness bending behaviors of the laminated MEE cylindrical shells are studied in detail.

A NURBS-based isogeometric boundary element method for analysis of liquid sloshing in axisymmetric tanks with various porous baffles

Abstract: An isogeometric boundary element method (IGA-BEM) based on the non-uniform rational B-splines (NURBS) is firstly performed to investigate the liquid sloshing in axisymmetric tanks with the porous baffles. The proposed method can completely maintain the advantages of the BEM that only the boundary of a domain requires discretization. By applying the NURBS basis functions it can exactly describe the geometry of the boundary. Meanwhile, it can also be obtained better solution field approximation at the domain boundary. Furthermore, as to the axisymmetric geometries of the containers considered in this paper, the 3-D liquid sloshing problems can be effectively reduced to 2-D ones on half of the cross-sections of the containers, which can significantly increase the computational efficiency. Meanwhile, the zoning method is employed in this paper to treat the arbitrary mounted porous baffles, and the Laplace equation is utilized as the governing equation of the potential flow model by assuming the fluid motion to be inviscid, irrotational and incompressible. Additionally, the weighted residual method together with the Green’s theorem is applied to develop the BEM integral equation. The natural sloshing frequencies and dynamic sloshing forces solved by the proposed method are compared with the available literatures and the traditional boundary element method (BEM). Good agreements are observed in the comparisons between numerical results and those of the existing literatures. And higher accuracy and convergence can be achieved by the proposed IGA-BEM method with significantly fewer nodes than the traditional BEM. Moreover, spherical tanks with the coaxial hemispherical, wall-mounted conical or surface-piercing cylindrical porous baffle, ellipsoidal tanks with spheroidal or surface-piercing cylindrical porous baffle, and the toroidal tank with tubular porous baffle are considered to investigate the effects of the porous-effect parameter, radius, length, height, horizontal and vertical semi-axes of the porous baffle on the sloshing characteristics (i.e. dynamic sloshing forces and surface elevations). The results show that the surface-piercing cylindrical porous baffle offers more noticeable suppression on sloshing response than the hemispherical and spheroidal porous baffles. Changing the radius of the tubular porous baffle has almost negligible effect on the sloshing force acting on the toroidal tank. The excitation frequency corresponding to the maximal value of sloshing force can be altered evidently by changing the porous-effect parameter of the porous baffle. In addition, choosing reasonable porous-effect parameter, radius, horizontal semi-axes and relatively larger length, height as well as vertical semi-axes for the porous baffles yields considerable suppression on the sloshing response.

Higher order semi-analytical solution for bending of angle-ply composite laminated cylindrical shells based on three-dimensional theory of elasticity

Abstract: This paper develops a high-performance semi-analytical numerical model to analyze the bending responses of the angle-ply composite laminated cylindrical shells with the fiber reinforced layers using the scaled boundary finite element method (SBFEM). As the thin-walled structures, the angle-ply composite laminated shells are assumed to be made of orthotropic materials in the cylindrical coordinate system. Both the geometric and basic variables are discretized by utilizing the two-dimensional (2D) high order spectral elements in the curved surface domain of the shells. According to the exact three-dimensional (3D) theory of elasticity rather than the approximate shell theories, the weak form of the partial differential governing equations for each layer of the composite laminated cylindrical shells in the cylindrical coordinate system are transformed into ordinary differential equations using the SBFEM. In the circumstances, there are no variables about the curved surface of shell in the SBFEM governing equations for each lamina, so that it can be analytically solved on the basis of the dual variable approach and the precise integration technique (PIT). Employing the interface continuity conditions of displacement between the layers, the complete SBFEM model with respect to the global stiffness matrix of the composite laminated cylindrical shell can be obtained. Unlike the general layerwise theories, which supposes that the basic variables varied linearly with the thickness coordinate, the through-thickness distributions of the displacement field in each discrete layer is assumed to be a quadratic polynomial with respect to the radial coordinate in this paper, thus the through-thickness stress field can be described more accurate. Numerical examples for solving the bending problem of composite laminated cylindrical shells are presented. As a result, the numerical efficiency, accuracy and applicability of the proposed formulations are confirmed by the comparison of the published results involving the distributions of the displacements and stresses through the thickness and along the circumferential direction for different staking configurations, geometric properties and boundary conditions.

The scaled boundary finite-element method – a primer: derivations

Abstract: Note: [255] Reference LCH-CONF-1998-009 Record created on 2007-04-24, modified on 2016-08-08

A porous wavemaker theory

Abstract: A porous-wavemaker theory is developed to analyse small-amplitude surface waves on water of finite depth, produced by horizontal oscillations of a porous vertical plate. Analytical solutions in closed forms are obtained for the surface-wave profile, the hydrodynamic-pressure distribution and the total force on the wavemaker. The influence of the wave-effect parameter C and the porous-effect parameter G, both being dimensionless, on the surface waves and on the hydrodynamic pressures is discussed in detail.

The scaled boundary finite-element method – a primer: solution procedures

Abstract: Note: [256] Reference LCH-CONF-1998-010 Record created on 2007-04-24, modified on 2016-08-08