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Selective laser melting (SLM) leads to high cooling rates and correspondingly high residual stresses, which can distort the printed part on the printing platform and even lead to part cracking and consequent print failure. The temperature profile and cooling rates during the SLM process are influenced by the surrounding powder bed and building platform, which can act as a significant heat sink depending on part design and platform arrangement. The new functionality of the Abaqus additive manufacturing simulation framework allows for separate modelling of solid (laser exposed) material, powder bed (not exposed) and platform (not exposed), as well as evolving heat transfer surfaces for the AM part. In this paper we highlight the influence of the surrounding powder bed and platform on the thermal characteristics of the printed part.

Customer Papers

In this study a 3D finite element model of the skull is created using CT scan data. All complexities of the skull geometry are simulated using ABAQUS. This numerical model is then subjected to frontal, lateral. vertical, occlusal and angulated impact conditions. Impact analysis is done and weak areas susceptible to fracture and hence failure are identified. Further fracture fixations of various designs and materials used in craniofacial fracture fixations are placed in different fracture situations in the virtual model and subjected to different impact conditions. This will enable the study of fracture and stability of the fracture of the skull under cranio facial fracture conditions.

Customer Papers

The working group of JANCAE was launched from the idea of providing a multidisciplinary forum for steel researchers, design engineers, and software engineers through the medium of advanced finite element codes. The subroutine library is called the Unified Material Model Driver for Plasticity (UMMDp). This paper introduces the development of UMMDp and discusses a simulation of a drawing and redrawing process using some yield functions for its applications with Abaqus.

Customer Papers

To assess the durability of a structure under random loading, the frequency based random response analysis is performed to obtain the stresses. Since random response analysis ignore the element damping, the results of the random response analysis can be unrealistically twisted if significant local element damping exists. This paper present an Abaqus FEA procedure to more realistically calculate the stress of the structure subject to random loading by submodeling and including element damping, which is a complementary method to Abaqus random response analysis procedure.

Customer Papers

In this paper, thermo-mechanical-metallurgical simulations of Ti-6Al-4V parts produced by SLM are validated against experimental measurements. The work involves the simulation of the SLM process and the prediction of location-specific microstructural features (such as grain size, morphology characteristics and phase fractions). A framework for more generally predicting the mechanical properties of printed parts is then presented. This involves the implementation of a novel mapping between microstructural quantities and tensile properties at each material point. The results demonstrate the potential that the powerful new features of Abaqus2017 have for simulating AM processes.

Customer Papers

Although additive manufacturing was first developed in the 1980’s, the technology is mainly applied for prototyping and tooling. The printing process is not well understood and controlled to be confidently used for printing of load bearing parts. Due to the complex geometry and the layer by layer printing process, parts as printed may show distortion, residual stress, delamination and failure that render the part unusable at the moment that it comes out of the machine. Finite element simulations of additive manufacturing can be very effective in understanding the cause of these defects and predicting the in-service performance of the printed parts. However, most finite element codes are not designed for simulating additive manufacturing processes.

Customer Papers

The buckling of a real, thin-walled shell is typically a local phenomenon, and it may be triggered by a small, local disturbance. Regarding these problems, a very slight imperfection can be the starting point from which local deformation is initiated and developed and, consequently, overall structural stability is lost. Therefore, it has been very difficult to pursue an analysis using the conventional approach, which is typically represented by the arc-length method. In this study, we provide an explanation for the artificial damping method from which we can overcome the difficulty in performing the analysis due to local instability.

Customer Papers

Finite-element analysis (FEA) has been applied to the development of expandable liner hangers (ELHs), helping optimize designs and reduce both development time and cost. In FEA models, displacement, or force, is prescribed on a fixed surface, which is accurate for mechanical expansion, but an approximation for hydraulic expansion. The difficulties for an accurate representation of hydraulic expansion include modifying the pressure boundary and determining the expansion pressure a posteriori by the force it takes to push the cone. This paper proposes a model to represent the hydraulic expansion process accurately without including fluid in the model. The model accounts for both the dependence of hydraulic-expansion pressure on expansion force and the varying pressure surface.

Customer Papers

The SIMULIA Living Heart Human Model provides a unique testing environment where a pacemaker lead can be virtually inserted and mechanically deformed during the cardiac cycle. Once the mechanical deformation results are obtained, the long-term durability of the implant can be assessed. The virtual nature of the test provides a physiologically accurate methodology to test new and existing devices without exposing patients to un-necessary risk.

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Tech Notes

For the safe design of aircraft bleed air system ducts and assessment of ducts with minor cracks found in the quality inspection, it is required to understand and predict the crack behavior and leak-before-break air leakage. A leak before break is desired so a leak can be detected and a repair made before a structural failure. Measuring the leaked air temperature is a widely used technique to detect the leakage flow. The ground maintenance team uses thermal imagining and temperature probe, while the on-board system uses temperature sensor wires to detect the hot air leakage. In this study, the Extended Finite Element Method (XFEM) is used to evaluate if an initial crack will grow into unstable failure.

Customer Papers

The mechanical methods used to extract virgin oils from olives are of two types: the discontinuous system and the continuous system. In any case, the system defined as "continuous" is composed of several steps, not all of which are completely continuous, due to the presence of the batching device. The aim of this work was to design a prototype of a home olive oil extraction machine with a heating device to be placed immediately before the filtration step to facilitate solid / liquid separation. This strategy represents the first step towards the transformation of the step of mixing a discontinuous operation into a continuous real process. The design, analysis and simulation were done using Catia and Abaqus.

Customer Papers