Centre de ressources SIMULIA

One key aspect for the design of fast and flexible steam turbine operation is thermal stresses arising during transient operation. If the stresses exceed the fatigue limits of the material, the lifetime of the steam turbine is shortened. Detailed finite element analysis is applied during design phase to assess the effect of transient temperature and stress profiles on the complex geometries. A significant amount of design effort is invested to determine the optimal process parameters for start-up, in order to achieve the fastest possible starts without exceeding allowable material stress limits.

Customer Papers

Nearly no load bearing behaviour of reinforced concrete members allows such varied interpretations and complex discussions as the shear behaviour. Especially the three-dimensional problem of the punching shear failure of reinforced concrete members is internationally discussed. Nevertheless up to now, there is no unified design approach or even an overall accepted design model. Especially for large structural members, as they are commonly used in industrial structures and high-rise structures, the experimental background is missing. Because of extensive costs and very high test loads numerical solutions and FE-simulations are indispensable. By using Abaqus, finite-element simulations are currently performed at the institute for reinforced and prestressed concrete structures at the Ruhr-University Bochum.

Customer Papers

The automotive instrument panel is usually constructed with several kinds of polymer materials. Two major roles of the instrument panel are i) holding the instruments, such as velocity meter, tacometer, and control knobs, etc. and ii) protecting driver and passenger from the critical injury from secondary impact in crash. The thermal creep properties of a polymer are the keys for maintaining the shape through the thermal cycles, and the rate-dependencies and energy absorption characteristics are the keys for the crash performance. The creep behavior of a polymer is the main concern of this paper.

Customer Papers

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