SIMULIA Resource Center

Material degradation and dynamic loadings are the main reasons for the damage in metals. Material degradation was caused by crack initiation and fatigue or dynamic loadings are the source for crack growth. The precise and realistic modeling of inelastic behavior of metals is crucial for solving several problems in engineering fields. To predict the initiation and growth of damage, there are several failure models & theories available presently. In this paper, progressive damage and failure material model using explicit finite element techniques are applied to predict the failure of aluminum alloy.

Customer Papers

The coupled Eulerian-Lagrangian (CEL) method in Abaqus/Explicit is essential in component design of head protection systems at BMW Group as it allows an accurate modeling of the gas behavior. However, due to the nature of the algorithm, the modeling of the contact between inflator gas and airbag membrane is a challenging task. Using conventional modeling techniques, two airbag membrane sections are not able to separate again, as soon as they come into contact, as the membrane elements are embedded into Eulerian cells entirely filled with inflator gas. The proposed modeling approach overcomes this severe contact issue and allows separation of the membranes after having been in contact. The method has successfully been applied for airbag deployment simulations within the development process at BMW Group.

Customer Papers

In the vehicle design, the interaction between road and vehicle is the main criteria in order to meet the durability, NVH (Noise Vibration and Harshness) & handling performance. Potholes in the road can cause damage to the wheel, suspension and chassis components. Pothole size and vehicle speed were the main factors for the damage. The larger pothole can cause severe damage or alignment issues. Based on the severity of the impact, damage will happen to the wheel rim and there will be a reduction in the air pressure inside the tire. In long-term, it will damage the suspension or steering components and it can also lead to premature tire wear and poor handling of the vehicle.

Customer Papers

Thermoplastic polymers show significant nonlinear viscoelastic behavior due to which, after removing the applied load, these materials have some viscoelastic recovery over time before permanent deformation or set occurs. In this work, Abaqus PRF model is used to predict this time dependent viscoelastic recovery. Unlike linear viscoelastic model in Abaqus, PRF model can predict the typical nonlinear viscoelastic behavior of thermoplastic materials. Two types of testing, stress relaxation and cyclic loading at three different strain levels, are used to calibrate the coefficients of PRF model. SIMULIA’s optimization tool Isight is used to optimize these coefficients. Using the optimized coefficients, the PRF model is able to predict the time dependent nonlinear viscoelastic recovery of thermoplastic polymers.

Customer Papers

This paper builds on previous undergraduate research done on the analysis of a baseball bunt. In that situation the bat was held stationary, while the ball was launched at a given velocity. In this research, the bat is allowed to swing with the swinging motion controlled by the user. The end result is a determination of the optimal position to hit a ball during a bat swing on an approaching ball as well as the optimal swing pattern. The ball’s exit velocity and direction is obtained after the impact with the bat. The results will not only show the direction the ball will travel, but how far it will travel as well.

Customer Papers

During finite element analysis (FEA) of downhole tools, the fluid load acting on the tool chassis and completion system, such as hydrostatic pressure, reservoir pressure, or applied wellbore pressure, is simply represented by uniform static pressure. This approximation of fluid load has been shown to be effective and accurate enough for many applications and is widely accepted. However, this fluid load representation can be problematic in terms of trapped fluid because the pressure from trapped fluid, which is typically confined between seals in a closed or confined volume, changes with deformation or deflection caused by applied pressure or by axial tensile or compressive loads on surrounding structures.

Customer Papers

Simulations contain assumptions and uncertainties that a designer must evaluate to obtain a measure of accuracy. The assumptions of the product design can be differentiated from the ones for the solver and material model through the use of a mid-stage validation. An open loop validation uses a controlled test on a standardized part to compare results from a simulation to the physical experiment. From the validation, confidence in the material model and solver is gained. In this study, the material properties of a polypropylene are tested to characterize for an *ELASTIC *PLASTIC model in ABAQUS. A validation of a quasi-static three-point bending experiment of a parallel ribbed plate is then performed and simulated. A comparison of the strain fields resulting from the complex stress state on the face of the ribs obtained by digital image correlation (DIC) vs. simulation is used to quantify the simulation's fidelity.

Customer Papers

This paper showcases the capabilities of Abaqus explicit solver to simulate and solve problems involving huge plastic deformation due to caulking process. Caulking is a mechanical joining process achieved by plastically deforming a material in order to hold another material. This method is in research phase and being examined by engineers at Daimler and University of Erlangen-Nuremberg (Germany). This technique is mainly used in Permanent Magnet motors to hold the magnets in the rotor stacks. The objective of the simulation is to find optimum tool geometry, depth of tool penetration and location of penetration for caulking process. The process involves huge plastic deformation and is successfully simulated using Abaqus Explicit. This illustrates the effectiveness of numerical simulations, helping the designers in reducing the need for actual test bench with numerous high cost fabricated hardware setup and thereby saving huge R &D cost and time.

Customer Papers

The critical value of pressure drawdown (CVPDD) is a key parameter for controlling the production rate for most of the wells in weak sand formations and depends on the form of completion used, particularly in cases of high-pressure/high-temperature (HP/HT). This paper presents a simplified three-dimensional (3D) calculation of CVPDD on the basis of maximum plastic strain for a given well in offshore Gulf of Mexico. A fully-coupled, poro-elastoplastic model was adopted to simulate the porous flow that occurred simultaneously with matrix inelastic deformation. A submodeling technique was adopted to address the discrepancy between the scale of the oil field and that of the wellbore section.

Customer Papers

EXXONMOBIL ENERGY, PROCESS & UTILITIES

Tech Notes

In this work, a numerical-experimental study aimed to better understand the loading rate and damage mechanisms involved on the carried tube, as well as the local deformation response of the full scale component when loaded under real loads are presented.

Customer Papers

Abaqus/Explicit is a well-established and widely used FEM solver for crash and pedestrian safety simulations. However, due to the large number of degrees of freedom, simulation time is still a limiting factor especially in context of structural optimization. In typical crash simulation, a large portion of the model undergoes only elastic deformation. Hence, model order reduction (MOR) methods can bring a significant decrease in the computational time. While Abaqus/Standard already offers several reduction methods, MOR is currently not applicable for Abaqus/Explicit. The purpose of this work is to enable MOR for explicit finite element models by use of superelements. Reduced mass and stiffness matrices are generated by Abaqus/Standard and transferred to the explicit solver through a VUEL subroutine.

Customer Papers