SIMULIA Resource Center

This study is focused on the assessment of the application of numerical simulations done with ABAQUS in the development of car seat cushions made of polyurethane foam. First, mechanical simulations of simple tests were carried out using a hyperelastic constitutive model of ABAQUS in order to adjust its parameters with real test data. Then, a static indentation test, which reproduces the mechanical response of a seat under the load of a dummy occupant, was simulated. The indentation curve was validated with real test results in a first approach. Validation of the contact pressure field is still to be done.

Customer Papers

New approach for solving Fluid Structure Interaction in aerospace application is presented in this paper. The proposed approach is based on the two-way coupling between CFD code FlowVision and FEA code ABAQUS. The codes are coupled directly without using any 3rd party software or intermediate structure. A direct link offers a full control over the load transfer and interpolation error free data exchange between the codes. The direct link is implemented using special meshing techniques (submerged meshes in FlowVision). FE mesh is subtracted from the Cartesian CFD mesh; all links between CFD mesh cell and outside faces of the finite elements are preserved.

Customer Papers

Experimental evidence of certain adhesive materials reveals a hardening regime with a pronounced strength difference between tension, torsion or combined loading. The results for the stress-strain curves are strongly rate dependent. Additionally a softening regime is observed, also dependent on the stress state of tension, torsion or combined loading. For simulation of these phenomena a Perzyna type flow parameter is introduced, It is formulated on the basis of an overstress function dependent on the first and second basic invariants of the related effective stress tensor.

Customer Papers

Optimization is widely accepted in product development and engineering. Advances in automated software and computing power make it possible to quickly and thoroughly explore design spaces in a rigorous manner. In this Technology Brief, we will demonstrate a methodology that adds reliability and robustness considerations to a traditional stiffness optimization and apply it to the design of a composite aircraft winglet.

Customer Papers

For clinicians and medical device manufacturers, in-vitro and in-vivo testing of the knee are important methods for evaluating treatment techniques. However, numerical models that can provide much of the same information will become of more service and are a new focus of the modeling community. A continued effort has centered on specimen-specific anatomical and functional models, in terms of both geometry and mechanical properties of the tissue constituents. Here, a specimen-specific model of the knee is presented that includes the femur, tibia, and four main ligaments. Solid models based on CT and MR scans of a human knee joint were meshed in Patran and assembled for solving in Abaqus 6.7-1.

Customer Papers

The deviatoric response of the Marlow model in Abaqusis defined by test data from a single mode of deformation. For example, the model can be defined with uniaxial tension data or uniaxial compression data but not with both (except in very limited cases involving 1-D elements). The fact that the Marlow model depends only on the first strain invariant causes the limitation. This paper shows that the Marlow model in Abaqus is a special case of a hyperelastic potential function which involves the first and second strain invariants. The extended Marlow model is defined by uniaxial tension and equibiaxial tension data.

Customer Papers

Oblique elastic impact of spheres and the related case for cylinders have been studied cases for many years in simulations of systems with loose supports, such as heat exchanger tubesupport interaction, as well as granular flows and robotic task modeling. The problem is a relative simple one in the class of transient frictional contact problems in that the stresses away from the contact zone are typically neglected. The available continuum model solutions from literature show some very interesting features. For near normal angles of incidence, these solutions combine a Hertzian contact stress solution in the normal direction with a partial-slip shear stress distribution in the tangential direction, in which a central portion of the contact zone is sticking while the coincident points of the outer annulus slide relative to one another.

Customer Papers

High precision reduction gears are composed of many cranks and gears which are in high stress contact through bearings. In order to precisely evaluate stresses in critical components, an attempt was made to analyze a complete model of a high precision reduction gear taking into account the contact conditions between the parts. Using the latest contact analysis function of ABAQUS 6.6, a 650,000 element model with 190 contact surfaces was successfully analyzed in under 24 hours. The results revealed the exact stress distribution in each part based on the local deformation of the components. This achievement could be a breakthrough for rational design and satisfy the growing demand for higher durability under higher load within limited space.

Customer Papers

Demands for state-of-the-art product developments are stronger than ever. Nowadays all industries are subject to accelerating changes in production and development and increasing aggressive competition. Complex demands can be fulfilled by applying simulation (ABAQUS) and optimization technologies (TOSCA) in an early phase of the virtual product development process. Product cycles have to become shorter by an increasing product complexity. This paper will describe the usage of automatic structural optimization methods within an early design phase of the development process for modern combustion engines used by FEV.

Customer Papers

Embossing of polymeric films destined for usage in the personal care marketplace is an industrial process that produces a very fine pattern, barely discernible to the naked eye, yet has a significant influence on some market-driven properties; more bulk, a soft and smooth touch, reduced crinkling noise and lower gloss. However this comes at a cost to the mechanical properties such as stiffness and ultimate strength capability. The paper discusses the computational approach, presents results of simulations performed in Abaqus/Explicit for an example 16 micron film and compares to experimentally measured values.

Customer Papers

There is increasing interest in the use of organic matrix composite materials in aerospace, as it is commonly stated that composite materials show good fatigue properties. This is rather difficult to quantify. Fatigue testing to obtain a S/N curve or a Range-Mean diagram for a composite material is fraught with difficulties; test specimens are prone to significant manufacture variation and it is time consuming to get data for high fatigue life. It is recognized that microcracks exist in composite components that would normally be considered “undamaged”. It has also been found that such cracks show evidence of crack growth during fatigue testing, although such growth is tiny in the length scale of the component.

Customer Papers

Thermal technologies are widely used for the heavy oil recovery. The thermal processes usually consist of some variation of Cyclic Steam Stimulation (CSS), steam flood or Steam Assisted Gravity Drainage (SAGD). These thermal recovery applications have experienced numerous well casing failures around the world, often resulting in loss of wellbore integrity, lost production and added costs. The primary casing failure mechanisms include casing connection leakage and/or parting due to excessive casing strain and wellbore serviceability difficulties due to large casing deformation associated with casing buckling and shear.

Customer Papers