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Bird strike events are a potential dangerous problem faced by flight safety nowadays. These events are usually simulated through numerical approaches due mainly to the technical difficulties and high costs associated with experimental tests. Definition of structures within appropriate non-linear finite element codes is now well known and developed, however, bird models vary considerably between workers. Differences in density, shape and aspect ratio are easy to see. Differences in mechanical properties are not as transparent. Unless data to define analytical birds can be justified against viable sources, it is unlikely that certification of structures by analysis alone will be successful. Similar thoughts apply when considering substituting real birds for synthetic birds in testing.

Customer Papers

It is sometimes necessary to strategically place temporary checkpoints in theatre. One such tool for creating an effective checkpoint is a deployable spike strip. One fault of the current system is that puncturing and deflating the tires may not be sufficient to bring the car to a halt. The U.S. Army proposed a request for improvement to design a new spike strip that actually causes the vehicle to come to a stop once the deployed system is rolled over. Tests of this new system are both costly to run and time consuming. A finite element simulation of the proposed system was created in Abaqus/Explicit to provide insight into how the system operated. Once set up, the model could then be used to down-select between subsequent iterations.

Customer Papers

In this paper, we present the workflow starting from the structural information through the FE mesh creation and population of its properties to the final 3D finite element based geomechanical modeling. The resulting 3D stress field around salt structures helps to significantly improve the wellbore stability predictions. The workflow described provides an efficient way to create realistic 3D finite-element simulations from complicated structural data. It is optimized for the best resolution around the area of interest (well trajectory) while limiting the size of the numerical problem to an order that can be handled in reasonable times.

Customer Papers

During the last twenty years, composite materials have gained great popularity in many applications such as aerospace, naval and wind turbines. Despite their wide use, the behaviour of composite materials still needs to be thoroughly investigated, especially during and after failure. Only a deep knowledge of these phenomena could maximize the benefit achieved by their use. Many failure criteria have been published in the last thirty years. Among them, the three-dimensional criteria (considering also the out of plane stress) have received particular attention. The present work has focused on the implementation of threedimensional failure criteria (Puck and Hashin 3D) in the commercial Finite Element program ABAQUS, using a USDFLD subroutine.

Customer Papers

In this study Virtual testing was performed using both Abaqus/Standard and Abaqus/Explicit, using a dedicated user-defined material model developed at Fokker Landing Gear. In this material model the composite constituents (fibers and resin) are modelled as separate materials with their own specific material and failure behavior. The crucial interaction between the fibers and resin is accounted for using a new analytical approach. Damage between plies is accounted for using cohesive surfaces.

Customer Papers

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.

Customer Papers

The present paper is concerned with modelling damage and fracture in notched woven fabric composites. Previous experimental work has shown that damage at a notch in a variety of GFRP and CFRP composites based on woven fabric reinforcement comprises matrix damage and fibre tow fracture along the plane of maximum stress. It is these experimental observations that inform the failure modelling developed here, in which a cohesive zone approach is used within a 2-D finite element framework.

Customer Papers

The cold expansion processes have been used for many years in the aeronautical industry in order to improve the fatigue life of structural components. The physical phenomenon underlining such improvement is well understood, however there is still not a recognized general method to provide accurate estimations for each specific problem. This work presents an attempt by Airbus Military (AIM) to develop a methodology based on analytical procedures in order to estimate the crack initiation in big aluminium alloy lugs fitted with bronze cold expanded bushings from Fatigue Technology Inc.

Customer Papers

The solution of manufacturing problems in minimally invasive medical devices poses the quadruple challenge of providing solutions as soon as possible in order to maximize operation of the process lines, limiting the project to a budget which is considerably lower than usually allocated for R&D, obtaining results for fairly complex nonlinear problems with enough accuracy to detect the effect of dimensional variability in very small parts, and documenting the procedures thoroughly and formally for ulterior validation, approval and insertion into the product lifecycle management of devices whose impact on human lives is critical. This paper shows several cases in which these challenges are faced with the aid of nonlinear simulation using Abaqus/Standard.

Customer Papers

Durability analysis of a powder metal automotive engine component main bearing cap is typically performed assuming uniform material properties. However, the mechanical properties of powder metal (PM) components vary significantly with density. Mississippi State University developed mathematical-based user material subroutines VUMAT and UMAT in Abaqus to model the compaction and sintering processes of powder metal components. This model can predict the distribution of material density during PM compaction analysis in Abaqus/Explicit. In this paper, based on the density distribution from compaction analysis of a PM main bearing cap, material properties are mapped onto the PM cap for durability stress analysis in Abaqus/Standard under typical automotive engine operating conditions.

Customer Papers

With the worldwide building industry constantly growing, more and more scaffolding manufacturers are entering the market. In order to assure the safety of workers, the capacity of these scaffolding systems must be accurately determined and updated with the release of new requirements. SP Technical Research Institute of Sweden has developed methods in which Abaqus is combined with experimental test data to determine the load classification and permissible loads of scaffolding systems according to European standards.

Customer Papers

The investigated components are seamless tubes used as housings of hydraulic cylinders mounted on earth moving machines. Accidental high working loads such overloads or machine misusing can be probable during their life, in this perspective, the failure mode and the limit load over which a rupture can be expected becomes extremely important. With the aim of investigating the failure severity of these components, a crack modeling for stress analysis has been performed.

Customer Papers