Search results for "Finite element"

Numerical analysis of composite plates with multiple delaminations subjected to uniaxial buckling load

2006

Abstract In this paper the buckling and post-buckling behaviour of unidirectional and cross-ply composite laminated plates with multiple delaminations has been studied. Finite elements analyses have been performed, using a linear buckling model, based on the solution of the eigenvalues problem, and a non-linear one, based on an incremental-iterative method. With non-linear method large displacements have been taken into account and also contact constraints between sublaminates have been added to avoid their interpenetration. It has been found that both delamination length and position and stacking sequence of the plies influence the critical load of the plate; furthermore, linear and non-li…

Integration of finite displacement interface element in reference and current configurations

2017

In the present paper the non-linear behaviour of a solid body with embedded cohesive interfaces is examined in a finite displacements context. The principal target is the formulation of a two dimensional interface finite element which is referred to a local reference frame, defined by normal and tangential unit vectors to the interface middle surface. All the geometric operators, such as the interface elongation and the reference frame, are computed as function of the actual nodal displacements. The constitutive cohesive law is defined in terms of Helmholtz free energy for unit undeformed interface surface and, in order to obtain the same nodal force vector and stiffness matrix by the two i…

Residual Stresses Induced by Cold Expansion of Adjacent and Cut-Out Holes

2012

Fatigue life of fastener holes can be enhanced via a cold-expansion process to introduce a compressive residual stress field around the hole edge and to reduce crack growth propagation. Considering that aerospace components contain multiple rows of holes, the present investigation focuses on the evaluation of the three-dimensional residual stress distribution in adjacent cold-expanded (CE) holes. The redistribution of residual stresses caused by a cut introduced between two adjacent holes was also investigated. Finite element (FE) analysis and experimental technique were used to assess the residual stress distribution in a 6082-T6 aluminum plate with two adjacent holes expanded sequentially…

Numerical simulation of fatigue-driven delamination using interface elements

2005

This paper presents a computational technique for the prediction of fatigue-driven delamination growth in composite materials. The interface element, which has been extensively applied to predict delamination growth due to static loading, has been modified to incorporate the effects of cyclic loading. Using a damage mechanics formulation, the constitutive law for the interface element has been extended by incorporating a modified version of a continuum fatigue damage model. The paper presents details of the fatigue degradation strategy and examples of the predicted fatigue delamination growth in mode I, mode II and mixed mode I/II are presented to demonstrate that the numerical model mimics…

A Boundary Element Formulation for Modelling Structural Health Monitoring Applications

2015

In this paper, a boundary element formulation for modelling pitch-catch damage detection applications is introduced. The current formulation has been validated by both finite element analyses and physical experiments. Comparing to the widely used finite element method, the current formulation does not only use less computational resources, but also demonstrates higher numerical stability. doi: 10.12783/SHM2015/221

The interphase elasto-plastic damaging model

2013

Heterogeneous materials present a mechanical response strongly dependent on the static and kinematic phenomena occurring in the constituents and at their joints. In order to analyze this kind of materials it is a common practice to distinguish a macroscopic length scale of interest from a mesoscopic one, where the mesoscopic length scale is of the order of the typical dimensions of the constituents. At the mesoscopic level the interaction between the units is simulated by mean of apposite mechanical devices. Among these devices is popular the zero thickness interface model where contact tractions and displacement discontinuities are the primary static and kinematic variables respectively. H…

B-Deformable Superquadrics for 3D Reconstruction

1995

We propose a new model for 3D representation and reconstruction. It is based on deformable superquadrics and parametric B-Splines. The 3D object deformation method uses B-Splines, instead of a Finite Element Method (FEM). This new model exhibits advantages of B-Splines It is significantly faster than deformable superquadrics without loss of generality (no assumption is made on object shapes,).

The MAST-FV/FE scheme for the simulation of thermohaline processes in variable density saturated porous media

2009

A novel methodology for the simulation of 2D thermohaline double diffusive processes, driven by heterogeneous temperature and concentration fields in variable-density satu- rated porous media, is presented. The stream function is used to describe the flow field and it is defined in terms of mass flux. The partial differential equations governing system is given by the mass conservation equation of the fluid phase written in terms of the mass- based stream function, as well as by the advection–diffusion transport equations of the contaminant concentration and of the heat. The unknown variables are the stream func- tion, the contaminant concentration and the temperature. The governing equatio…

The MAST-FV/FEM scheme for the simulation of thermohaline processes in density-variable saturated porous media

2008

Finite Element Method and Von Mises Investigation on Bone Response to Dynamic Stress with a Novel Conical Dental Implant Connection

2020

The bioengineering and medical and biomedical fields are ever closer, and they manage to obtain surprising results for the development of new devices. The field of simulations and studies in silica has undergone considerable development in recent years, favoring the advancement of medicine. In this manuscript, a study was carried out to evaluate the force distribution on the implant components (In-Kone® Universal) and on the peri-implant tissues subjected to loading. With the finite element analysis and the Von Mises method, it was possible to evaluate this distribution of forces both at 0 degrees (occlusal force) and at 30 degrees; the applied force was 800 N. The obtained results on this …