software

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.

Space flight re-entry vehicles impart highly dynamic loads on the crew and/or payload during a water landing. To understand the behavior of the vehicle/payload system as it makes impact, a predictive framework that can simultaneously model the structure, the highly deformable landing medium (water or soil), and their interaction is required. The coupled Eulerian-Lagrangian (CEL) method in Abaqus/Explicit provides the means for capturing these complex physical phenomena.

Composite structures often have a higher capacity for ab-sorbing energy than their metal counterparts. The crush-ing behavior of composite materials is complex, and the inclusion of composite components in vehicles for crash protection can necessitate expensive experimental test-ing. The ability to computationally simulate the crushing response of composite structures can significantly shorten the product development cycle and reduce cost in the aerospace, automotive, and railway industries.

Bird strikes cost the United States aviation industry tens of millions of dollars annually in aircraft damage and schedule delays. Increasing the ability of the aircraft to resist bird strike induced damage is one part of an overall approach to mitigating this expense [1]. Experimental bird strike testing is part of the certification process for certain aircraft component designs. If a subset of the tests can be replaced with computational simula-tion, the cost of the prototype testing can be reduced.

A mechanical system, such as aircraft landing gear, can have a large number of parts that interact in a complex nonlinear fashion. The challenge of simulating such a sys-tem lies not only in capturing the correct physical behavior but in using efficient analysis techniques. Different levels of modeling abstraction may be appropriate for different stages of the design process. Initial sizing and kinematics can be studied with a partially rigid representation, while final designs are more often analyzed with fully meshed flexible geometry.

Composite materials offer significant design advantages in the aerospace industry. High strength and light weight are the two most attractive features for aircraft and space vehicle designs. However, their complex material behav-ior makes analysis of these structures a significant chal-lenge, particularly in a high speed impact event. The ad-vanced composite modeling and industry leading simula-tion capabilities of Abaqus/Explicit make analysis of these challenging materials straightforward and allow accurate prediction of ballistic limit, damage and failure.

The use of composite materials in the aerospace industry is increasing. Composite materials offer a relatively high strength-to-weight ratio as well as the ability to create large, integrated structures. One composite component can replace 10 or more traditional metal parts, which can dramatically reduce manufacturing time and cost.