The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
About twenty years ago a NASA‐group around S. C. Chang began to develop a method using space‐time domains as elements for unstaedy flow computation. There are two kinds of elements. One within which the linearized form of the underlying differential equation is satisfied and one whithin which space‐time flux is conserved. Therefore the method is called conservation‐element solution‐element or shortly...
Shear‐locking is a significant problem when using the Finite Element Method (FEM) with standard lower order Langrangian shape functions. To avoid this effect we introduce the discontinuous Galerkin Finite Element Method (dG‐FEM) for linear elasticity. In addition to a standard integration scheme for the dG‐FEM we develop a mixed integration scheme and compare both with established finite elements...
This paper investigates the uncertainty of hyper‐elastic model, by random material parameters as stochastic variables. For its stochastic discretization a polynomial chaos (PC) is used to expand the coefficients into deterministic and stochastic parts. Then, from experimental data in combination with artificial data for elastomers the distribution of the force‐displacement curves are obtained. In...
We show how to use optimal experimental design methods for the parameter identification of short fiber reinforced plastic (SFRP) materials. The experimental data is given by computer simulations of representative volume elements (RVE) of the SFRP material. The experiments are designed such that a minimal number of RVE simulations is required and that the model response attains a minimal variance for...
In structural mechanics, when the design contains two different materials with opposite mechanical behaviours and costs, the optimum design cannot exactly found. In that case, numerical optimization algorithms are a good source. Reinforced concrete design shows that behaviour since concrete is a cheap material comparing to steel while the tensile strength of concrete is very low to use. The cross...
If Differential Evolution (DE) is applied to multi‐objective optimization problems, some of its features like automatic problem‐specific step‐size adaptation gets lost. This can be resolved by modifying the DE equations. Three strategies are proposed and compared with existing algorithms. It is shown, that the proposed strategies deliver a superior convergence and preserve the positive characteristics...
A monolithic approach is proposed that provides simultaneous modelling and analysis of the harvester, which involves surface‐coupled fluid‐structure interaction, volume‐coupled electro‐ mechanics and a controlling energy harvesting circuit for applications in energy harvesting. A space‐time finite element approximation is used for numerical solution of the weighted residual form of the governing equations...
On a microscopic length scale dual‐phase steels exhibit a polycrystalline microstructure consisting of ferrite and martensite. In this work it is assumed that the martensitic phase behaves purely thermoelastic while for the ferritic phase a thermoplastic material model was developed based on the assumption that the driving mechanism for persistent deformation is the movement of dislocations on preferred...
Modern vehicles are highly complex systems consisting of many subsystems in various physical domains, e.g. electric, electronic, hydraulic and control systems that dynamically interact. For any subsystem, there are tailored simulation tools with specifically developed and adapted numerical solvers. In this context, co‐simulation strategies are particularly attractive, where each submodel is solved...
In scientific computing there is a great interest in numerical simulation of fluid‐structure interaction (FSI) problems. Within this work a numerical approach to simulate fluid‐structure interactions between elastic structures and weakly incompressible fluids is developed. For the fluid part and the solid part the Smoothed Particle Hydrodynamics method (SPH) and the Finite Element Method (FEM) are...
In the present work, the behavior of heterogeneous magnetorheological elastomers undergoing large deformations under the action of magnetic fields is studied. First‐order computational homogenization is used to derive the homogenized stresses and magnetic inductions of the macro‐structure from the response of the underlying micro‐structure. Different types of boundary conditions are applied to solve...
Refractory materials such as magnesium oxide carbon (MgO‐C) composites are used in the steel‐making industry for furnaces, ladles or oxygen converters. A new class of composites are cellular MgO‐C materials, consisting of carbon foams filled with magnesium oxide and inclusions of gas filled pores. Cellular MgO‐C composites have the advantage of significantly improving the thermo‐mechanical properties...
In this paper, the constitutive modeling of nonlinear multifield behavior as well as the finite element implementation are presented. Nonlinear material models describing the magneto‐ferroelectric or electro‐ferromagnetic behaviors are presented. Both physically and phenomenologically motivated constitutive models have been developed for the numerical calculation of principally different nonlinear...
Long‐span bridges may collapse due to the interaction of turbulent wind flow and structural motion. The investigation of the fluid‐structure interaction requires appropriate models for the structure, the wind flow and the coupling between them. Modeling and simulation of the wind flow is still a challenging aspect. The aim of this paper is to show the application of Reynolds Averaged Navier‐Stokes...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.