Universal three‐dimensional connection hexahedral elements based on hybrid‐stress theory for solid structures

Abstract

SUMMARYHigh-performance hybrid-stress hexahedral solid elements are excellent choices for modeling joints, beams/columns walls and thick slabs for building structures if the exact geometrical representation is required. While it is straight-forward to model beam-column structures of uniform member size with solid hexahedral elements, joining up beams and columns of various cross-sections at a common point proves to be a challenge for structural modeling using hexahedral elements with specified dimensions. In general, the joint has to be decomposed into 27 smaller solid elements to cater for the necessary connection requirements. This will inevitably increase the computational cost and introduce element distortions when elements of different sizes have to be used at the joint. Universal connection hexahedral elements with arbitrary specified connection interfaces will be an ideal setup to connect structural members of different sizes without increasing the number of elements or introducing highly distorted elements. In this paper, the requirements and the characteristics of the hexahedral connection elements with 24 and 32 nodes will be discussed. Formulation of the connection elements by means of Hellinger-Reissner functional will be presented. The performance of connection elements equipped with different number of stress modes will be assessed with worked examples.

Advantages of the mixed format in geometrically nonlinear analysis of beams and shells using solid finite elements

“…In this way, solid-shell elements have now reached a high level of 1238 D. MAGISANO, L. LEONETTI AND G. GARCEA efficiency and accuracy and have also been used to model composites or laminated beams [11,13,15,16] and shell structures in both the linear [3,9] and nonlinear [1,2,12] range. Among the most effective and interesting proposals we refer to are the mixed solid-shell elements of Sze and coauthors [1,13,[16][17][18][19][20][21][22][23], which extend the initial PT18ˇhybrid element of Pian and Tong to thin shell.…”

Polyhedral elements with strain smoothing for coupling hexahedral meshes at arbitrary nonmatching interfaces

“…Some attempts have been made to apply polyhedral elements to FE analyses [29][30][31][32][33][34]. Most of these studies, however, adopted somewhat difficult and complicated approaches to formulating the shape functions of the polyhedral elements.…”

“…In most studies on polyhedral elements for use in FE analyses [29][30][31][32][33][34], these issues have been resolved through difficult and complicated processes. Here, to facilitate an efficient treatment of the shape functions, a strain smoothing technique in the cell-based smoothed finite element method (CSFEM) [8,[35][36][37][38][39][40][41][42][43][44] is introduced.…”

Finite Element Models of Elastic Earthquake Deformation

“…A comprehensive account of various mesh generation techniques is described and discussed in the textbook "Finite Element Mesh Generation" by Lo [50]; and in general, unstructured meshes are generated by the Delaunay triangulation, the advancingfront approach and the quadtree/Octree techniques etc., whereas structured meshes of hexahedral elements can be synthesized by some mapping and sweeping processes. Transition quadrilateral and hexahedral elements [51] and universal connection hexahedral elements [52] have also been developed for adaptive refinement analysis. However, in conjunction with the popular mesh generation methods mentioned here, other techniques could also be employed for specific applications to broad-scale earthquake problems.…”