Since 1960s, how to develop high-performance plate bending finite elements based on different theories has attracted a great deal of attention from element researchers, and numerous models have been successfully constructed. Among these elements, the most popular are usually formulated by two theoretical bases: Kirchhoff theory Mindlin-Reissener theory. Due advantages that only<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"...

SUMMARY In order to develop robust finite element models for analysis of thin and moderately thick plates, a simple hybrid displacement function method is presented. First, the variational functional complementary energy Mindlin–Reissner plates modified be expressed by F , which can used derive components satisfying all governing equations. Second, assumed resultant force fields, satisfy related equations, are derived from fundamental analytical solutions . Third, displacements shear strains...

According to the “four-step” braiding technique, this paper analyzed movement laws of internal space yarns in projection plane and space, established a 3D seven-direction braided composite material solid finite element model by combining observed yarn directions on surface side preform. Based Hashin criterion, progressive damage failure analysis method was adopted study shear mechanism composites. The effect angles elastic properties crack propagation path fabric discussed. modes mechanisms...

The Qushi rhyolites, situated in the eastern sector of Tengchong terrane, are critical to understanding Early Cretaceous tectono-magmatic evolution Eastern Tethyan Tectonic Domain. Zircon LA-ICP-MS U-Pb geochronology indicates crystallization ages 118.3–120.5 Ma, with Ti-in-zircon temperatures 641–816 °C (mean = 716 °C), representing magmatic activity terrane. Inherited zircons within rhyolites yield a zircon age ca. 198.5 corresponding 615–699 657 implying potential presence an Jurassic...

Summary A recent unsymmetric 4‐node, 8‐DOF plane element US‐ATFQ4, which exhibits excellent precision and distortion‐resistance for linear elastic problems, is extended to geometric nonlinear analysis. Since the original US‐ATFQ4 contains analytical solutions pure bending, how modify such formulae into incremental forms applications design an appropriate updated algorithm become key of whole job. First, trial functions should be at each iterative step in framework Lagrangian formulation that...

Purpose Quantitatively detecting surface defects in a circular annulus with high levels of accuracy and efficiency has been paid more attention by researchers. The purpose this study is to investigate the theoretical dispersion equations for circumferential guided waves then develop an efficient technique accurate reconstruction pipes. Design/methodology/approach methodology applied determine pipelines includes four steps. First, work carried out developing appropriate pipe. In phase,...

The functionally graded (FG) flexoelectric material is a potential to determine the structural morphing of aircrafts. This work proposes penalty 20-node element based on consistent couple stress theory for analyzing FG plate and shell structures with complex geometric shapes loading conditions. Several numerical examples are examined prove that new can predict size-dependent behaviors effectively, showing good convergence robustness. Moreover, results reveal exhibits better bending...

Summary The unsymmetric finite element method is a promising technique to produce distortion‐immune elements. In this work, simple but robust 4‐node 12‐DOF quadrilateral membrane formulated. test function of new determined by concise isoparametric‐based displacement field that enriched the Allman‐type drilling degrees freedom. Meanwhile, rational stress field, instead one in original formulation, directly adopted be element's trial function. This obtained based on analytical solutions plane...

Summary In bending problems of Mindlin–Reissner plate, the resultant forces often vary dramatically within a narrow range near free and soft simply‐supported (SS1) boundaries. This is so‐called edge effect or boundary layer effect, challenging problem for conventional finite element method. this paper, an effective method analysis such developed. The construction procedure based on hybrid displacement function (HDF) [1], simple hybrid‐Trefftz stress proposed recently. What different that...

Summary A new C 0 8‐node 48‐DOF hexahedral element is developed for analysis of size‐dependent problems in the context modified couple stress theory by extending methodology proposed our recent work (Shang et al., Int J Numer Methods Eng 119(9): 807‐825, 2019) to three‐dimensional (3D) cases. There are two major innovations present formulation. First, independent nodal rotation degrees freedom (DOFs) employed enhance standard 3D isoparametric interpolation obtaining displacement and strain...

Purpose The paper aims to the size-dependent analysis of functionally graded materials in thermal environment based on modified couple stress theory using finite element method. Design/methodology/approach formulation is developed within framework penalty unsymmetric method (FEM) that C 1 continuity requirement satisfied weak sense and thus, 0 continuous interpolation enhanced by independent nodal rotation employed as test function. Meanwhile, trial function designed functions weighted...

Summary In this work, the recently proposed unsymmetric 4‐node 12‐DOF (degree‐of‐freedom) membrane element (Shang and Ouyang, Int J Numer Methods Eng 113(10): 1589‐1606, 2018), which has demonstrated excellent performance for classical elastic problems, is further extended modified couple stress theory, to account size effect of materials. This achieved via two formulation developments. Firstly, by using penalty function method, kinematic relations between element's nodal drilling DOFs true...

Purpose The purpose of this paper is to give a review on the newest developments high-performance finite element methods (FEMs), and exhibit recent contributions achieved by authors’ group, especially showing some breakthroughs against inherent difficulties existing in traditional FEM for long time. Design/methodology/approach Three kinds new FEMs are emphasized introduced, including hybrid stress-function method, displacement-function method Mindlin–Reissner plate improved unsymmetric FEM....

Abstract This work proposes a penalty 20‐node hexahedral element for size‐dependent electromechanical analysis based on the consistent couple stress theory. The nodal rotation degrees of freedom (DOFs) are used to approximate mechanical rotation, meeting C 1 requirement in weak sense by using function method, and effectively enhance standard isoparametric interpolation determining displacement test function. normalized functions that satisfy relevant equilibrium equation strain compatibility...

Purpose The purpose of this paper is to propose an efficient low-order quadrilateral flat shell element that possesses all outstanding advantages novel shape-free plate bending and plane membrane elements proposed recently. Design/methodology/approach By assembling a hybrid displacement-function (HDF) HDF-P4-11β (Cen et al. 2014) stress-function (HSF) HSF-Q4θ-7β 2011b) with drilling degrees freedom, new 4-node, 24-DOF (6 DOFs per node) successfully constructed. trial functions for...