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A finite element analysis methodology was developed to simulate brittle crack initiation, ductile or brittle crack propagation and ductile crack arrest in a single simulation using ABAQUS. Ductile fracture was modeled by employing element deletion when the equivalent plastic strain reached a critical value. Within the same FEM, brittle fracture was modeled by incorporating cohesive behavior between contact surfaces defined along the expected crack face. While this method was not as accurate as an FEM incorporating J integral calculations, its simplicity allowed simultaneous incorporation of brittle and ductile fracture.

Customer Papers

Modern sealing technology in powertrain and exhaust applications of the automotive and heavy-duty industries utilizes Multi-Layer-Steel (MLS) gaskets for cylinder head gaskets (CHG) and exhaust gaskets. In light of more stringent requirements towards emissions and fuel economy, the increased application of shear forces on those gaskets due to vibration and thermal expansion have a major influence on the durability and wear of the gasket layers.

Customer Papers

Durability is a key measurement of prosthetic heart valve function. Assessment of fatigue life requires accurate estimates of the stresses induced during the cardiac cycle. Finite element (FE) studies have been used to estimate peak stresses in valves, and computational fluid dynamics (CFD) studies have been used to model blood flow around valves. Fluid-structure interaction (FSI) studies are less common, in part because the closure of the valve creates CFD domain pinching. The smoothed particle hydrodynamic (SPH) analysis method in Abaqus/Explicit overcomes this difficulty. In this Technology Brief, the SPH technique will be used to determine the FSI response of a generic prosthetic heart valve.

Solution Briefs

Today, computational analysis is systematically used for the development of new models. However, traditional simulations and optimization studies require an exchange of data between the CAD and CAE applications that is extremely time-consuming and tedious. Improving CAD-CAE interoperability and automating the optimization process is a key to reducing model development time.

Customer Papers

In this Technology Brief, a co-simulation approach between Abaqus/Standard and Abaqus/Explicit is used to predict vehicle behavior on durability test tracks. The vehicle body and suspension, which typically respond in a mildly nonlinear manner, are solved using the implicit solution technique. The tires, which experience impact loading and rapid changes in contact state, are solved using the explicit solution technique. The co-simulation approach allows for an efficient analysis by capitalizing on the strengths of both solution techniques simultaneously.

Solution Briefs

This paper summarizes the methodology to design fracture-split (FS) connecting rod using CAE tools, ensuring product quality with reliability and rapid response in terms of study and implementation. FS connecting rod is first manufactured as single piece, then precisely cracked-off, aided by laser score-line, to produce jagged surfaces which provides perfect alignment, higher strength and keeps production costs low.

Customer Papers

Friction stir welding is used to fabricate the NASA Ares I rocket upper stage fuel tank. The friction stir plug weld fills the hole left when the stir weld tool is removed. NASA engineers want to examine fracture conditions in the plug weld due to possible imperfections to assure safety and reliability. An automated and parametric crack mesh generator is needed to quickly and easily examine numerous cases. The plug weld crack meshing approach and its reliance on Abaqus for analysis is discussed, and crack mesh basics are reviewed. The choice of crack shape and 39 additional geometric and mesh control parameters, such as the plug diameter, transverse weld sizes, and plug bevel angle affect how the crack mesh is created.

Customer Papers

In the production of aerospace engine components, metal cutting processes are characterized by a strong demand for increased productivity that does not compromise the high quality of the product. In aerospace machining applications on hard-cut materials like: nickel based alloys, titanium alloys, etc, it is fundamental to keep under control the local cutting zone phenomena in order to assure the final product quality. The machining process design development can be summarized by the following steps: definition and verification of the Part Program (PP) through dedicated CAD–CAM software applications, post processing of the produced PP, CNC machine simulation and physical tryout.

Customer Papers

Under contract from Wright-Patterson AFB (WPAFB), ATA Engineering, Inc., (ATA) has performed a study of “snap-through buckling” of a panel on a hypersonic vehicle under the influence of fluctuating pressures. Snap-through occurs when the elastic stiffness of the structure is cancelled by the effects of compressive stress within the structure. If this effect causes the structure to suddenly displace a large amount in a direction normal to the load direction then it is classical bifurcation buckling. If there is a sudden large movement in the direction of the loading it is snap-through buckling.

Customer Papers

Currently, the typical Isight user is a specialist in process integration, optimization and creation of complex processes. He can create complex processes with different external programmes quickly and has a good knowledge of data structure, interfaces and useful control scripts. If some problems appear, the expert user with his experience can react and solve the problem very quickly. By contrast, non-expert users need much more time to build or customise the same complex processes and to solve occurring problems. Therefore, there is a clear barrier for non-expert users to work on complex processes with Isight.

Customer Papers

Suspension rubber bushingsin full vehicle models are usually represented with nonlinear spring elements. However, when bushings are preloaded or deformed in diagonal direction, the spring element models tend to express inaccurate movement. In this paper, suspension rubber bushings are modeled with solid finite elements. We established a technique enabling to evaluate the nonlinear large deformation behavior ofrubber bushings. This modeling technique is also able to improve simulation accuracy compared to the conventional modeling technique.

Customer Papers

This paper shows how multiple analysis techniques converge in Abaqus/Standard to produce simulation-driven design of restrained PVC pipe joints. PVC is known to exhibit viscoelastic behavior as it approaches its glassy transition temperature. This is used to produce pipe sockets by heating and forming them over a mandrel. A type of pipe joint which is becoming very successful includes other elements such as special seals made or rubber and steel, and restraint mechanisms made of ductile iron, which remain trapped inside the socket when it cools. At room temperature, elastic-plastic behavior of PVC dominates. As the restraint mechanism grips a spigot inserted in the socket, the pipe is indented by sharp teeth, causing severe plastic strain and mesh distortion. This makes a good case for an Adaptive Langragian-Eulerian domain.

Customer Papers