software

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.

The Vernay VernaFlo® flow controls are custom-designed fluid flow management devices used in a wide range of applications and systems where consistent, reliable op-eration is essential. Elastomeric rubber components in these devices deform under the influence of upstream variations in fluid pressure. These deformations adjust the orifice diameter and help maintain a constant down-stream flow rate. In this Technology Brief the perform-ance of a custom VernaFlo® device is evaluated using the fully coupled fluid-structure interaction solution provided by the Abaqus co-simulation capability.

Engineering problems that involve the coupled response of a flowing fluid and a deforming structure constitute a broad class referred to as fluid-structure interaction (FSI). The interaction can be mechanical, thermal, or both. Many important problems involve some form of FSI, but the coupling effect is often ignored because of a lack of readily available solution technology. To address this limitation, Dassault Systèmes SIMULIA Corp. and Fluent, Inc. have partnered to provide a coupled solution capability.

As the maximum speed of bullet trains continues to increase, overheating and thermal deformation/stress on brake systems are going to be critical for emergency stops. Precise prediction of the maximum temperature is needed for the design of brake systems, especially  for both discs and linings, where how to handle the high speed spinning of discs is the point of the heat/structure coupled analyses. Abaqus provides couple of potential methods but each one had critical shortcomings.

One key aspect for the design of fast and flexible steam turbine operation is thermal stresses arising during transient operation. If the stresses exceed the fatigue limits of the material, the lifetime of the steam turbine is shortened. Detailed finite element analysis is applied during design phase to assess the effect of transient temperature and stress profiles on the complex geometries. A significant amount of design effort is invested to determine the optimal process parameters for start-up (e.g.

Electrically operated high temperature furnaces and reactors are used in many industrial manufacturing processes such as sintering or single crystal growth in order to allow for the required process conditions. In view of their outstanding characteristics refractory metals are ideally suited as materials for the resistive heating elements. Nevertheless, significant and lifetime-limiting irreversible deformations of these elements can be frequently observed which are assumed to be caused by a combination of temperature expansion, electromagnetic forces, and high temperature creep effects.

Identication of fatigue cracks in turbo-machinery components is a vital but costly effort. This work focuses on nonlinearities in the response behavior resulting from the opening and closing of cracks that results in super-harmonic resonances due to harmonic excitations. Experimental results for a cracked cantilever beam are presented as well as the results from numerical simulations of an integrally bladed compressor disk FE model. Identication of sensitive vibration features is expected to contribute to the development of automated crack detection techniques for aircraft engine disks.

Today manufacturing companies are more and more often characterized by a growing product
and processes complexity. Projects needs the participation of a pool of companies that have to

The modelling of welds is desirable to predict the distortion of components during manufacture, the position and magnitude of peak residual stresses and to predict metallurgical effects in specific regions. Welds are a complex modelling problem requiring both thermal and structural solutions. This has lead to the development of several weld-specific simulation packages and codes for finite element analysis packages. This paper describes the application of the newly developed Abaqus 2D Weld Modeller to simulate the residual stress field in ferritic weld test specimens.

Electric Boat’s design process involves evaluating the structural stability of ring-stiffened cylinder structures through finite element analyses to simulate a static pressure load. Each design revision of the cylinders must be evaluated to verify that the structure meets the required stress criteria for the static pressure load; any revision to geometry or material would require the design to be reevaluated. Additionally, it is critical that the weight of the structure is kept as light as possible while still satisfying all stress and deflection criteria.

The paper presents a numerical simulation of the drop test in a still water for the multi-component box structure. The complexity of the problem is in the strong fluid-structure interaction (FSI) between the box and the water free surface. The numerical simulation of the drop test is performed with two software tools: Abaqus and FlowVision through the direct coupling interface, which manipulates, on the Abaqus side the Lagrangian finite-element mesh and on the FlowVision side the Eulerian finite-volume mesh with sub grid geometry resolution.

This paper covers finite element (FE) analysis and optimization of a spring orthosis, constructed from a pre-impregnated carbon-fibre epoxy composite material. The spring orthosis is one of the most advanced aids that are used in the orthopedist industry. The work has been performed in collaboration with Ortopedteknik, Borås Hospital, at FS Dynamics in Gothenburg. The purpose of the analyses was to find weaknesses of how the orthosis is built today and to give suggestions of how to change its properties and behaviour. The orthosis has two major interesting areas, the spring and the toe.

Biomechanics testing of the lumbar spine, using cadaveric specimens, has the advantage of using actual tissue, but has several disadvantages including variability between specimens and difficultly acquiring measures such as disc pressure, bone strain, and facet joint contact pressure. A simulation model addresses all of these disadvantages. The objective of this work is to develop a method to simulate the biomechanics of the lumbar spine. A process is currently being used to convert a CT scan of a lumbar spine into a simulation model.

Total knee replacement gives proven good results for isolated patello-femoral osteoarthritis, but patello-femoral arthroplasty may be more appropriate because only the joint compartment is replaced. Although the femoral component of a patello-femoral prosthesis is smaller than in total knee arthroplasty, it is unknown whether strain-adaptive periprosthetic bone remodeling occurs following patello-femoral arthroplasty. The aim of the study was to evaluate and compare the stress shielding effect of prosthetic replacement with Finite Element (FE) modeling.

Genetic algorithms have become one of successful tools in design and topology optimization. The optimization module based on genetic algorithms was developed and employed in Abaqus/CAE by GUI and kernel scripting. The new module extends advanced functionality of Abaqus/CAE allowing to perform optimization directly in Abaqus Unified FEA product suite from SIMULIA. The genetic algorithms implemented in optimization approach are based on available GPL libraries.

In this study we compare various way of quantifying high cycle radial fatigue behavior in a percutaneous Mitral repair device using Goodman methods. In order to provide an improved representation of the tissue-device interaction, we use an Ogden hyperelastic model to  simulate the native vessel with parameters obtained from pressure-diameter test data of human cadaver heart coronary tissue, and published data presented in previous work.

Prediction of respiratory motion has the potential to substantially improve cancer radiation therapy. A nonlinear finite element (FE) model of respiratory motion during full breathing cycle has been developed based on patient specific pressure-volume relationship and 4D Computed Tomography (CT) data. For geometric modeling of lungs and ribcage we have constructed

Computational modeling of stents can provide insight into critical locations (high stress/strain regions), help with design iterations/optimization, and reduce the need for bench-top testing. This study focuses on the developmental efforts to create a material model that can capture the mechanical response of poly-L-lactide (PLLA), the backbone of Abbott Vascular’s ABSORB Bioresorbable Vascular Scaffold (BVS). PLLA is an anisotropic, viscoplastic material.