Centro de recursos de SIMULIA

This work describes a numerical methodology based on the Finite Element approach able to simulate the dynamic maneuver of the full vehicle running on fatigue reference roads. The basic idea of present work stays in combining a moderately complex and general tire model with traditional full-vehicle methods, including both implicit and explicit finite element techniques, in order to predict – within the early design phases when no prototypes are available - the loads transmitted to the vehicle running on the real fatigue reference roads. Some issues related to application of tire finite element model to a long simulation time in an explicit solution have been discussed. The methodology has been successfully applied to Fiat light commercial vehicle, New Fiorino, chosen as test case for this work.

Customer Papers

With increasing train speeds and platform overcrowding, passenger safety is becoming an increasing concern. Nabtesco Corporation has developed a platform safety device to allow commuters to safely enter and exit train carriages. CAE was used to confirm the device could be safely operated, even after accidental impact by a train. Predicted stress values were found to be sensitive to the brake parameters used in the model, and so using actual brake performance should greatly increase the accuracy. However, even when using simple brake parameters the stresses could be predicted to within 50%.

Customer Papers

Turon’s methodology for determining optimal analysis parameters for the simulation of progressive delamination is reviewed. Recommended procedures for determining analysis parameters for efficient delamination growth predictions using the Abaqus/Standard cohesive element and relatively coarse meshes are provided for single and mixed-mode loading. The Abaqus cohesive element, COH3D8, and a user-defined cohesive element are used to develop finite element models of the double cantilever beam specimen, the end-notched flexure specimen, and the mixed-mode bending specimen to simulate progressive delamination growth in Mode I, Mode II, and mixed-mode fracture, respectively.

Customer Papers

Monte Carlo reliability calculations for high-reliability systems are very computationally expensive. Variance reduction techniques optimize this process greatly and directional simulation is one such technique. Directional simulation is particularly valuable for high reliability systems where the failure surface is highly curved or dislocated. Subsea pipe-inpipe structures in certain classes represent such a system and Abaqus is ideally equipped to solve this structural problem, which involves contact with friction, buckling, plasticity and fabrication imperfections amongst other phenomena.

Customer Papers

In the design of a modern lightweight structure, it is of technical importance to assure its safety against the buckling under the applied loading conditions. For this issue, the determination of the critical load in an ideal condition is not sufficient, but it is further required to clarify the postbuckling behavior, that is, the behavior of the structure after passing through the critical load. One of the reasons is to estimate the effect of practically unavoidable imperfections on the critical load and the second is to evaluate the ultimate strength to exploit the load-carrying capacity of the structure. For the buckling problem of circular cylindrical shells under axial compression, a number of experimental and theoretical studies have been made by many researchers.

Customer Papers

The ability to accurately calculate the risk of fretting fatigue in the contact interfaces of clamped sub-assemblies in medium-speed diesel engines has become important as a consequence of, among other things, performance demands. The application of the finite element method to fretting fatigue risk evaluation is a demanding task because the contact has to be modeled very accurately with the help of, among other things, a very dense mesh to capture the steep stress gradient in a partial slip situation. A three-dimensional model of the contact between a counterweight and a crankshaft in a Wärtsilä diesel engine was made by using Abaqus.

Customer Papers

Typically thermo-mechanical analysis including complexities such as contacts and bolt preloads are carried out using three dimensional models. These analyses require significant time and effort in FE model building, analysis setup, solution, and results processing. It also requires special effort to ensure it is error free. This paper also talks about simplified yet almost equally accurate modeling and analysis method for thermo-mechanical analysis using brake fade test simulation as an example. This methodology is based on use of Abaqus/Standard Axisymmetric analysis technique modified to represent effect of discrete bolting, bolt preloads, and contacts within various components of the assembly.

Customer Papers

This work is concerned with the Abaqus implementation of a suitable CAE methodology to get the most benefits of structural adhesive bonding. In this study, we are interested in cohesive debonding where the adhesive thickness and its non-linear behavior are of major importance. When subjected to loading, significant stress field gradients may develop around outer edges of the joint. Because such regions are sites for failure initiation, a specific mesh refinement is needed. Using SIMULIA solutions, an efficient discretization strategy, inspired by the p-FEM, is suggested and is implemented as an Abaqus user element. As the approach is suggested to be used in real applications, a validation example has been chosen to show the suitability of the methodology on coarse meshes.

Customer Papers

Analysis methodologies developed for evaluating three threaded and coupled connectors quantitatively are presented. Two new non-dimensional parameters for assessing the seal leakage and load shoulder separation are introduced for the purpose. Stress Amplification Factor (SAF), defined in API Specification 16R, is scrutinized for what type of stress is to be used and which reference point the alternating stress is measured from. As a result of it, loading sequence Mean Tension with Two Alternating Moments (MT2AM) is proposed for SAF calculation.

Customer Papers

Electrostatic Discharge (ESD) is a phenomenon where static electricity discharge happens between two electrically charged objects when they come into contact with each other, such as the human body and an electronic device. This high voltage ESD pulse generated from the human body can enter the electronic device if touched, causing damage to IC circuits inside it. With increasing operating speed and decreasing operating voltage of electronic components the problem of ESD is a severe source of interference which can produce damage, upset or failure in electronic systems.

White Papers

The number of patients in need of medical aid devices (anti-decubital systems, medical shoes, orthoses etc.) has risen drastically due to demographic changes and an unhealthy lifestyle. Such devices however, are not always helpful at affected soft tissue body sites. Sometimes they even aggravate the situation, leading to costly complications such as pressure sores, infection and amputation. Therefore, better assessment and understanding of device caused mechanical loading, involving critical stress and strain at the affected tissue region, is essential to more effectively design such devices. A method to approach such problems has been developed.

Customer Papers

The objective of this paper is to introduce an economical and user-friendly technique for estimating a specific type of finite element simulation uncertainties, or, "error bars," for a class of mathematical models, of which no closed-form or approximate solution is known to exist. Using Python, Abaqus-Python, and a public-domain statistical data analysis software package named Dataplot, we present a design-of-experiments-based Python-Dataplot-Uncertainty Plug-In (PD-UP) to estimate the finite element simulation uncertainties in a mathematical model due to variability in modeling parameters such as material property constants, geometric parameters, loading rates, etc.

Customer Papers