SIMULIA Resource Center

Accurate modeling and simulation of brittle armor panels under projectile impact is a challenging problem involving costly experimental characterization of material properties and verification of ballistic impact response with actual test data. The nature of impact of brittle armors, specifically those made of cementitious materials, is a problem of much complexity, due to high-rate fragmentation caused by strong compressive shock waves followed by reflected tensile waves. Traditional Lagrangian FEM of these problems can introduce errors and issues of convergence as a direct result of the resulting large deformations of free surfaces. Introducing element erosion can resolve some of the issues related to excessive distortion of elements, but presents new problems involving conservation of mass.

Customer Papers

Traumatic brain injury (TBI) is one of the world’s major causes of death and disability. To aid companies in designing safer and improved protective gear and to aid the medical community in producing improved quantitative TBI diagnosis and assessment tools, a multiscale finite element model of the human brain, head and neck is being developed. Recorded impact data from football and hockey helmets instrumented with accelerometers are compared to simulated impact data in the laboratory. Using data from these carefully constructed laboratory experiments, we can quantify impact location, magnitude, and linear and angular accelerations of the head. The resultant forces and accelerations are applied to a fully meshed head-form created from MRI data by Simpleware.

Customer Papers

voestalpine Krems is a roll forming corporation constantly working on the improvement of product quality as well as the development of new production processes. Abaqus is used in both areas. Within this paper both approaches are shown and compared to each other. The first example problem shows a planetary rolling mill where we performed a feasibility study. The second example problem covers the whole roll forming process. The results are directly fed back to our engineering team to optimize the process. Critical further processing steps can be modeled afterwards by using predamaged parts.

Customer Papers

Drilling through salt has created increasing challenges for the oil and gas industry. In many cases, deepwater exploration around the world requires drilling through salt layers above oil and/or gas reservoirs. Borehole closure and instability due to salt creep are two major concerns in designing completions for production wells drilled through salt layers. Similar issues also occur where gas storage caverns are built in salt formations. Pressure changes that occur in the salt cavern during operation can cause cavern closure and instability.

Customer Papers

In this Technology Brief, we discuss the sudden expansion problem f the FDA Benchmark Noozle model. Overall, Abaqus/CFD results were found to match reasonably well with experimental data and were competently at par or superior to other package software results. The k-ω SST model was found to fare the best among the three turbulence models for the higher Reynolds number cases.

Solution Briefs

Tetra Pak has used numerical simulation tools for plastic injection molding (Moldflow) and structural analysis (Abaqus/Implicit and Abaqus/Explicit) for many years. Today these two simulation tools are used independently of each other without any coupling. How these two disciplines can be combined to better predict the mechanical response of a polymer component is presented in this work. The manufacturing process, in this case injection molding, creates the mechanical properties of the produced polymer part. Process settings, material selection and molding tool geometry affect the polymer flow, material orientation and rate of crystallinity.

Contact

Dynamic problems involving contact are of great importance in industry related to mechanical and civil engineering, but also in environmental and medical applications. Regarding the implicit dynamic structural analysis, Abaqus/Standard has the HHT (Hilber-Hughes-Taylor) method which is a family of unconditionally stable one step methods for the direct time integration. This method is extended from well known Newmark beta method.

Customer Papers

The study of fluid dynamics has evolved so much from mathematical modeling to numerical calculations. Recent advancement in numerical calculations introduced by Abaqus for fluid analysis is Coupled Eulerian-Lagrangian (CEL) method. The new method provides quicker solution for a Fluid-Solid Interaction (FSI) analysis. However, when a new method introduced, it is important for the users to know the accuracy, efficiency or even the limitation of the method. The objective of this study is to validate the famous flow over a sphere using CEL method in comparison to the experimental data.

Customer Papers

A mesh objective crack band model is implemented in the generalized method of cells (GMC) micromechanics model to predict failure of a composite repeating unit cell (RUC). The micromechanics calculations are achieved using the MAC/GMC core engine within the ImMAC suite of micromechanics codes, developed at the NASA Glenn Research Center. The microscale RUC is linked to a macroscale Abaqus/Standard finite element model using the FEAMAC multiscale framework (included in the ImMAC suite). The effects of the relationship between the characteristic length of the finite element and the size of the microscale RUC on the total energy dissipation of the multiscale model are investigated.

Customer Papers

Future hypersonic vehicle will operate in an extreme environment, which includes extreme aerodynamic heating, fluctuating pressure and acoustic loading. Hypersonic vehicle must be reusable, lightweight and affordable in such environment. For hypersonic flight, the structure experiences complex aero-acoustic loads. The design of structure depends on the ability to predict response and life of structure in extreme environment. This paper presents a detailed investigation of the interactions and interplay among these parameters as evidenced by the nonlinear response of the panel.

Customer Papers

When a panel of an elastomeric material, such as polyurethane, is subject to large cyclic in-plane displacements which result in cyclic compressive buckling, cracks will be observed to form at the center and edges of the panel. These cracks tend to propagate across the panel in the region of maximum deflection. If the magnitude of the applied cyclic deflection is held constant, the crack growth rate is observed to be nearly a constant over much of the width of the panel. This paper will present a method for evaluating the strain energy release rate in compressively flexed elastomeric panels and present results showing the influence of basic geometric parameters on the strain energy release rate.

Customer Papers

Improvements in technology and computing have provided highly detailed representations of the human body for biomedical simulations. One specific application is the use of these computational phantoms for particle transport in MCNP, a general purpose particle transport code developed by Los Alamos National Laboratory (LANL). Traditional mathematical based phantoms, such as the ICRP 23 Reference Man, MIRD-5 Adult Male and the Snyder phantom, use equations to specify the surfaces and volumes of organs within the body. Image based models, such as the Visible Photographic Man (VIP-Man), Zubal model, and Extended cardiac-torso (XCAT), use segmented CT and MRI data to construct a three dimensional model of the body.

Customer Papers