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In recent years Fokker Landing Gear has developed a proprietary material model to more accurately model composites. In this material model the fibers and resin are included as separate materials with their own specific material and failure behavior, both with a limited number of material parameters and with clear physical meaning. The interaction between the fibers and resin is accounted for using a new analytical approach. Because the inclusion of fibers is done using a vector based approach the model is valid for any fiber structure.

Customer Papers

In the development of the new bi-level train KISS Abaqus/Standard and Abaqus/Explicit have been intensively applied to optimize the structure with respect to stiffness and strength as well as to crashworthiness. Models up to 3 million shell elements have been used to prove the strength of the load carrying structure with respect to the standard EN12663-1. By using Abaqus/Standard the calculation times were minimized allowing for a significant number of iterations to optimize the structure with respect to lightweight engineering and with respect to a reduction of manufacturing time. Additionally, the Abaqus/Standard result files were used to investigate the fatigue strength of the structure, especially of the welds, with FEMFAT, a postprocessor code from Magna Powertrain.

Customer Papers

Composite structures can be vulnerable to several types of damage. Abrasion and low to mid velocity impacts can result in deep scratches impacting the surface plies. In this study, the delamination which is induced by scratches under tensile loading are investigated using experimental and finite element techniques. A finite element approach based on progressive damage analysis implemented in VUMAT subroutine and a cohesive zone model using Abaqus are performed to simulate the behavior in the composite specimen. Scratches at different depths with different angles in carbon fiber-epoxy laminates are modeled to study the influence of the scratch size and the stacking sequence effects. Experimental results show the delamination propagates between layers.

Customer Papers

The use of renewable energy sources is being expanded strongly all over the world. Wind power plays an important role in this field. In recent years, the output of wind turbines has increased continuously. In such plants, the important mechanical components include bearings which, with increasing output, are becoming increasingly larger. Therefore the Schaeffler Group took the decision to build the largest bearing test rig in the world. This makes it possible to strongly drive forward the development of large size bearings for wind turbine manufacturers. With a maximum bearing outside diameter of approx. 3.5 m, the highly versatile test rig can also be used to test all other large size bearings.

Customer Papers

A discrete multi-mode damage initiation, propagation, and interaction tool is implemented within Abaqus’ implicit solver for residual strength and life prediction of bolted joints with a given initial damage resulting from the fabrication and installation process. A discrete crack network model (DCN) for damage progression prediction has been developed by combining mesh independent matrix cracking with cohesive zone delamination models at the ply interfaces. A regularized X-FEM (Rx-FEM) framework maintaining the distribution of the Gauss integration points without element slicing has been utilized for implementation of the solution module for residual strength prediction under monotonic loading.

Customer Papers

The goal of this work was to simulate both the flow in a rocket engine nozzle and the resulting flow-induced transient loads on the nozzle. This unsteady nozzle flow results in structural dynamic excitation, which contributes not only to nozzle stress and deformation but also to the dynamic loads that are transmitted to the rest of the engine. This paper demonstrates the capability of a coupled fluid-structure interaction (FSI) simulation for predicting side loads on a rocket engine nozzle. The capability was demonstrated using the space shuttle main engine (SSME) during a portion of the engine startup sequence.

Customer Papers

The paper describes using of Abaqus for evaluating the behavior of car plastic parts which are exposed to high temperature and self weight (plus another load) for long time. Car plastic parts (inside and outside) are subjected to complex loads – temperature, vibration and environmental conditions. It is a challenge to prepare simulations which correctly describe the complex behavior - temperature dependent, time dependent of stress-strain behavior. To capture visco-elastic behavior we chose a creep description of the material.

Customer Papers

Regarding FEM for welded structures, shell elements are mostly used to capture the structural behavior very efficiently. Depending on the choice of the element order, mesh size, etc. local nominal or even hot spot stresses can be calculated. These values can be assessed directly according to typical standards, i.e. Eurocode, DVS, FKM-Guideline etc. In our contribution we will present a method, which allows an efficient fatigue assessment of welded structures, based on deriving relevant stress quantities from the results of continuum models. This method has been implemented in the commercial software LIMIT for typical standards.

Customer Papers

Three-dimensional woven composites that are becoming increasingly popular in aerospace applications have superior through-the-thickness strength, stiffness, and thermal conductivity compared to conventional 2D laminated composites. However, despite their advantages, many details regarding the mechanical behavior of 3D woven composites are not as well-known as they are for traditional laminated composites. Microcracking of carbon-epoxy composites during resin curing is one important example. The main goal of this study is to improve the understanding of cure-induced microcracking through the development of realistic numerical models validated with experimental data.

Customer Papers

Abrasive wear of tillage tools by hard soil particles is a major concern in the agricultural industry. Previous efforts to understand the effect that various factors such as the soil composition and the tool material have on tool wear have been primarily experimental in nature. Since a large number of factors influence tool wear during tilling operations, it is impractical to expect the experimental studies to be exhaustive. The finite element method offers an additional tool that can be used in conjunction with experimental studies to further the understanding of wear in tillage tools. In this paper, preliminary results from a numerical study undertaken to study abrasive wear of tillage tools by soil particles are presented.

Customer Papers

This study is focused on analysis of post-repair behavior of composite structures. The objectives are to a) develop efficient computational approach for repaired areas, capturing processes of both damage initiation and growth; and b) demonstrate it in Abaqus on representative examples of composite repair designs. The approach is based on cohesive elements (CE), and the robust nature of generated numerical predictions is shown. Thus, the approach provides a very convenient FEA implementation and, on the other hand, can generate sufficient accuracy for repair-related design and service decisions. Results of parametric studies are presented for selected cases to demonstrate sensitivity of damage tolerance of repaired zones to input parameters.

Customer Papers

Unified analysis platform is the core value for SIMULIA Abaqus with realistic simulation. This paper demonstrated a successful integration of design process with various design requests where CEL dominated slamming wave impact transient analysis, CFD deal with ventilation and thermal analysis, and CMA was in charged with composite structure layup and manufacturing process management. This unified platform dramatically decreased yacht design cycle time and brought highly accurate simulations with complex physical problems.

Customer Papers