With the IGA (Isogeometric Analysis) technological approach [1], the transfer processes from CAD to CAE can be simplified in the future and false predictions due to discretization effects can be reduced. In recent years, IGA and the corresponding toolset has increasingly developed into a setup that comes close to industrial use [2]. In order to test the use of IGA in industrial environments, a body in white (BIW) that was previously modelled with a „classic“ FE approach was also modelled with IGA and installed in a so-called hybrid model in a full vehicle crash simulation. For this purpose, the CAD data used as the basis for the FE model creation was used to directly create IGA surfaces. The aim of implementing a body in white using IGA was, on the one hand, to look at the processes in terms of usability, automation capability and implementation quality; and, on the other hand, to understand how hybrid crash simulations behave in terms of computing time and stability. In order to see different design effects in crash simulations, a front crash and a side crash were carried out and compared with existing FE models. The investigations show the entire process, from geometry conversion to full vehicle simulation and explain the findings in comparison with the FE model.
Isogeometric sheet metal forming simulation is a promising numerical technique utilized for predicting the behavior of sheet metal parts during the forming process, aiming to establish a stronger connection with Computer Aided Design (CAD) descriptions. This approach combines the well-established framework of traditional finite element analysis (FEA) with the power of non-uniform rational B-splines (NURBS), known as isogeometric analysis (IGA). Unlike the conventional FEA framework, IGA directly employs the ansatz space of the CAD geometry for analysis, thereby enabling analysis on the exact geometry. Additionally, the smoothness of NURBS basis functions offers enhanced simulation accuracy and a larger timestep in explicit dynamics.
Driven by the increasing need for seamless integration between Computer-Aided Design (CAD) and Computer-Aided Engineering (CAE), Isogeometric Analysis (IGA) emerged with the groundbreaking research conducted by Hughes et al. [1] in 2005. Unlike standard Finite Element Analysis (FEA) that typically employs 𝐶0-continuous Lagrange polynomials as basis functions, IGA utilizes smooth spline-based basis functions, the same as the ones used to describe the CAD geometries. The usage of consistent basis functions offers the potential to bridge the gap between CAD and CAE.
During the last years the capabilities of both LS-DYNA and ANSA are in continuous progress in terms of creating and analyzing IGA models, especially in crash and safety discipline. Automotive industry studies the behavior of ever more complex mechanical parts by running simulations using both FEA and IGA within a context where robustness and automation are probably the most important keywords. Pre – processing such parts with Isogeometric Analysis gives more accurate results in terms of displacements but robustness is yet to come. Describing and analyzing the parameters of an IGA simulation singularities, plays an important key role in the latest developments of the ANSA pre – processor, opening the way to study new models of high complexity and build hybrid models.
Heliostats are concentrating mirrors which track the sun to direct light onto a receiver in concentrating solar power (CSP) systems. Heliostat cost and performance are major contributors to the capital cost of CSP systems and their levelised cost of energy. For this reason, several existing heliostat mirror facet designs utilise low-cost stamped supports which are laminated to glass mirrors to impart stiffness and maintain shape accuracy of the optical surface, whether curved or flat.
In 2005, Hughes et al. [1] introduced isogeometric analysis (IGA). As opposed to standard Lagrange polynomial-based finite element analysis (FEA), IGA utilizes the same shape functions employed in computer-aided design (CAD) for numerical analysis. In the last decade, the development of IGA in LS-DYNA was mainly focused on thin-walled structures modelled as either structured trimmed or unstructured isogeometric shells. Currently, there is growing interest in the analysis of more complex engineering parts. This requires the use of accurate solid finite elements. It is well known however that rather poor computational performance can be achieved by invoking low-order solid elements. Recently, the potential benefits of volumetric B-spline finite elements have been successfully demonstrated by Meßmer et al. [2], [3]. This led to an increased customer interest and thus to the development of trimmed isogeometric solids in LS-DYNA. This paper provides an overview of basic concepts and current capabilities of trimmed isogeometric solids in LS-DYNA.
Isogeometric Analysis (IGA) [1] is a novel Finite Element Analysis (FEA) technology based on splines known from Computer Aided Design (CAD). In an isoparametric sense, IGA uses the higher-order and higher-continuity spline basis functions, e.g., Non-Uniform Rational B-Splines (NURBS), not only to describe the model geometry, but also the solution field. This may yield a more accurate geometry description, higher solution accuracy and a larger time step in explicit analysis compared to conventional FEA.
EXPERIENCE WITH CRASH SIMULATIONS USING AN IGA BODY IN WHITE