SIMULIA's blog

The National Highway Traffic Safety Administration (NHTSA) mandates the use of certain test procedures to determine automobile roof crush resistance. In the test the force-deflection behavior of the roof structure is meas-ured by quasi-statically pressing a precisely positioned rigid plate against the automobile. As part of the design process, the test is often simulated analytically. As with many quasi-static processes, the roof crush resis-tance test can be simulated in Abaqus/Standard or Abaqus/Explicit.

A methodology to study friction-induced squeal in a com-plete automotive disc brake assembly is presented. The analysis process uses a nonlinear static simulation se-quence followed by a complex eigenvalue extraction to determine the dynamic instabilities that are manifested as unwanted noise. The effects of assembly loads; nonuni-form contact pressure between the brake linings and disc; velocity-, temperature-, and pressure-dependent friction coefficients; friction-induced damping; and lining wear can be included. The methodology is demonstrated with a representative disc brake assembly.

Spot-welded, thin-walled curved beams, which constitute the main structural members in many automobile and other ground vehicle body structures, play a significant role in absorbing energy during a collision. Due to their extensive use, it is important to study the collapse charac-teristics of these curved members (Ref. 1). Abaqus/Explicit can be used effectively to simulate the quasi-static collapse of spot-welded structural members accu-rately.

A wide range of loading conditions must be considered in the design of a tire. Computational simulations of a quasi-static, steady-state dynamic and nonlinear transient dy-namic nature must be completed. In addition, the com-plexity and size of typical tire models highlight the need for efficient solution techniques.

Spudcans are conical footings used as foundations for offshore platforms. Installation in soft marine soil forces them deeply into the seabed, inducing gross motion and severe plastic deformation in the soil. A pure Lagrangian-based finite element approach for modeling spudcan installation and extraction can be very difficult. Because the mesh moves with the material, ele-ment distortion typically accompanies severe deformation and convergence difficulties follow.

On August 1, 2007, the I-35W highway bridge over the Mississippi river in Minneapolis, MN collapsed. The sub-sequent National Transportation Safety Board (NTSB) investigation identified the U10W truss node as a likely initiation site for the failure. (Bridge main truss nodes were numbered from the south starting at 0. U indicates a node along the upper chord, and L indicates a node along the lower chord. E and W indicate a node on the east or west truss) [1, 2, 3].

Assessing the strength of soil slopes and investigating the means for increasing their safety against failure are cru-cial in construction projects involving large soil masses. Slope stability analyses have traditionally been performed using a limit state approach. However, any presence of reinforcement or local heterogeneity necessitates the use of numerical techniques such as finite element analysis. Abaqus/Standard can be used for modeling reinforced soils and can thus help geotechnical engineers in deter-mining optimal reinforcement sizes and placement con-figurations.

Pullout resistance of driven foundation piles often in-creases with time in a process known as pile “setup.” The consolidation of the surrounding soil after the pile is driven plays a dominant role in the setup process. Finite element modeling of pile setup can help in obtaining reli-able estimates of the increase in pile resistance, which would allow for reductions in pile lengths, pile sections, or sizes of the pile driving equipment.

Finite element modeling of prestressed concrete contain-ment vessels (PCCVs, Ref. 1) for nuclear power plants poses special challenges. PCCVs, which are heavily rein-forced structures, are designed to deform beyond the cracking limits of the concrete. Abaqus has been used extensively for analyzing such structures in the nuclear utility industry (Ref. 2) and can be used to assess and improve the performance of these and other similar rein-forced concrete structures.

Construction of earthen dams entails sequential place-ment and compaction of soil layers and the subsequent fill-up of the embanked reservoir. In the design of earthen dams, two potentially critical events must be considered: the rapid emptying (or drawdown) of the reservoir and the dynamic loading of an earthquake. The possibility of dam failure in these situations depends on the respective build-up and dissipation of the fluid pore pressure in the soil.