SIMULIA Ressourcen-Center

Because of its high viscosity in melted state, PTFE powder is typically sintered first as large billet, from which parts are machined such as films, seals, etc. In large industrial sinter billets that can reach beyond 1-2 meters in size, PTFE's low thermal conductivity and large crystallization volume change could introduce significant residual stress during cool down from sinter temperature, resulting in billet cracking and difficulties in the subsequent machining step. FEA models were developed to predict the residual stress in the billet for a given temperature profile.

Customer Papers

The principle of achieving high strength and superior properties in metal alloys through the application of severe plastic deformation has been exploited in the metal processing industry for many decades. The High Pressure Torsion (HPT) process is one of the most promising techniques for imposing very high strains to a bulk solid without introducing a significant change in sample dimensions. The HPT process involves large shear and compressive plastic deformations, and offers the possibility to deform the material under very high hydrostatic pressures (up to several GPa), with continuous control of the degree of deformation.

Customer Papers

The structural component investigated is a roll mill bar which sustain a plug for a transversal rolling of steel pipes. The improvement of the stiffness of this component is the target of the simulation to achieve the desired flexional displacement. An optimization tool is used to achieve the target in a proper and fast way. A 3D FEM model is developed to perform several different static analyses as basis of optimization process. The bending response of the structure is studied on the basis of the real working condition introducing the loads measured in the plant. Explicit model is then used to simulate the new stiffness in the expanding roll process. The main purpose of the improved stiffness is to stabilize the rolling process to maintain the bar and the plug aligned with roll axis, keeping the setup of the machine.

Customer Papers

Helical buckling analyses are performed primarily to determine the critical effective axial load at which the inner pipe of a pipe-in-pipe (PiP) system snaps into a sinusoidal or helical buckling deformation mode. The expected behavior, when a flowline is compressed within a larger diameter tubular, is that it will first develop a sinusoidal buckle pattern as it lies along the bottom of the larger diameter pipe. Further compression of the inner pipeline will ultimately cause it to snap into a helical deformation pattern, which will lift the inner flowline off of the bottom of the outer pipe. The axial force that triggers the sinusoidal buckling is denoted as Fcs and the larger force needed for helical buckling is denoted as Fc.

Customer Papers

Offshore pipeline design is a multidisciplinary field of engineering that covers route optimization, mechanical wall thickness design, fracture mechanics, flow assurance, stress analysis, geotechnics.For decades, pipelines have been designed pursuing a stress based approach, based on analytical methods and semi-empirical rules of thumb. However, the challenging conditions in oil and gas exploration and production dictate the use of sophisticated numerical tools to assist the pipeline design engineer. In particular, pipe-soil interaction is a complicated phenomenon that governs the response of the offshore pipeline to operational load patterns.

Customer Papers

In this work the quasi-static response of thermoplastic butt-joint stiffened beam in bending conditions is modeled. In these panels, the stiffener is connected to the skin by a shortfiber reinforced filler. Although this type of connection performs very well in a pull-off loading (fracture loading is 10 times higher than welded connection), optimization is required regarding its impact performance. The main issue concerning this loading type is the extreme resistance to impact until a certain threshold, upon which the stiffener-skin connection fails in an instable manner, however leaving only barely visible damage on the skin side.

Customer Papers

A methodology has been developed for characterising the mechanical behaviour of concrete, based on the damaged plasticity model, enriched with a user subroutine (V)USDFLD in order to capture better the ductility of the material under moderate confining pressures. The model has been applied in the context of the international benchmark IRIS_2012, organised by the OECD/NEA/CSNI Nuclear Energy Agency, dealing with impacts of rigid and deformable missiles against reinforced concrete targets. A slightly modified version of the concrete damaged plasticity model was used to represent the concrete. The simulation results matched very well the observations made during the actual tests.

Customer Papers

Lightweight technology is a very important part of today’s engineering practice. The discussion of CO2 emissions and fuel consumption gets more and more important. Hybrid vehicles could save fuel, but are also heavier. AUDI has made a sign with innovative new technologies in the hybrid models Q5, A6, A8, and has shown with the new A6 and A3 that a car could be lighter than its previous release. All these leading technologies are summarized in Audi Ultra. There are several ways to get a lighter construction. This paper is attended to describe the advanced technology of simulating short fiber reinforced plastic engine parts.

Customer Papers

Contact lenses correct the optics of the ocular system by placing a refractive element over the cornea. Modern lens materials are comprised of 30-90% water and exhibit viscoelasticity, hyperelasticity and thermal dependencies. Contact lens materials have traditionally proven to be extremely difficult to characterize for a number of reasons, primarily because the properties are dependent upon the processing conditions of the lenses themselves and the size and geometry of contact lenses makes them unsuitable for use in standard test apparatuses. In order to better characterize our contact lens materials we have developed an In Situ lens compression testing instrument, wherein a lens is placed in solution and compressed between two flat surfaces while applied force is recorded.

Customer Papers

This paper presents the implementation of an industrial FE methodology to predict delamination and debonding for a composite wing box subjected to tire impact. This numerical approach has been developed in Abaqus/Explicit v6.10 and is calibrated and validated using a building block strategy, where analysis has been correlated to test at each level. Ply-to-ply interface and bondline properties have been determined by an exhaustive test campaign to calibrate the cohesive element material cards. Intra-laminar damage model based on the Hashin model has been used together with cohesive elements to model the ply interface and bondlines. The methodology, successfully validated using the aforementioned building block approach, was then applied to tire impact on a composite wingbox structure.

Customer Papers

Rocket and missile systems are often kept in launch tubes until they are fired. Dimensions of the tubes are determined by the munitions inside them. In some cases, due to space and weight limitations, launch tubes must match certain dimensions other than imposed by the system. Inner diameter of the launch tube is mainly determined by control surface span. Thus folding the control surfaces decreases space occupied in the tube. In foldable wing mechanisms, wings are held in folded position in the tube. After munitions leave the tube, wings erect and are locked secure in unfolded position. These mechanisms contain a spring like element that stores necessary energy to unfold the wing and a locking pin that secures the wing in desired position.

Customer Papers