Project IMVAL (completed 04.2007)
Project content and results
The aim of the joint project was to develop, manufacture, analyze, characterize and apply a new lightweight composite material. The composite material consists of geometrically well-defined small and specifically very light mineral foam spheres (inserts), which are shaped into a macroscopically geometrically defined form and infiltrated with a liquid plastic or metal (matrix) via a casting process. The resulting creation of many interfaces and cavities and the possibility of integrating force introduction and fastening elements lead to significantly reduced weight with simultaneously defined adjustable deformation properties. Due to the low specific weight, the uniform and easily reproducible foam structure, the good shaping possibilities and the favorable energy absorption capacity, this cellular composite material offers particular advantages for lightweight construction, for example in automotive engineering. In particular, the composite can be used as a core material for sandwich constructions, thus providing good stiffness and strength properties.
The favorable energy absorption capacity of closed-cell foams also promises functionally highly modulable solutions for crash problems (e.g. energy-absorbing structural components for head impact on the hood, defo elements in a skewed crash or lightweight stiffening elements for side impact). Another advantage is the relatively low material costs resulting from the use of recycled products (e.g. bottle glass or filter dust from power plants) for the inserts.
Within the research project, the mineral foam granules were optimized and manufacturing technologies for the composite were developed. In order to open up the wide range of applications within lightweight construction, suitable material models with experimentally determined material parameters have been set up for the computer simulation of the material and component behavior with regard to deformations and internal stresses using the finite element method (FEM). The knowledge of the material properties including the damage behavior, as well as the availability of suitable material laws for FEM applications in the viscoelastic and elastoplastic range and at high strain rates as they occur in crash applications, should enable the use of the new composite material in the automotive industry as well as in other industries in which lightweight construction technologies play a major role.
In addition, design guidelines were drawn up for designing with this lightweight material in a way that is suitable for materials, production and testing. These were developed on the basis of specific design tasks in the field of thin-walled frame and shell structures.
Material parameterization was carried out by means of microcomputer tomography (µCT) and 3d image processing in order to verify the specific setting of material parameters in samples and in the component and thus to open up quality assurance for component manufacture.
The development process and the production of molded parts were set up in order to cover the entire process chain from material production to the finished product and to demonstrate the economic manufacturability for series production. The final objective of this research project was the production of a prototype of a lightweight molded part which is to be developed, manufactured, machined and tested under operating conditions using all the technologies described.
Cooperation Partners
Research partner:
Competence Center of Lightweight Design at the University of Applied Sciences in Landshut
Subproject: Material laws for cellular composites in the time-free elasto-plastic range
Ingolstadt University of Applied Sciences
Subproject: Material laws for cellular materials at higher strain rates
Fraunhofer Institute for Industrial Mathematics (ITWM)
Subproject: Analysis of the structure of mineral foam composites
Foundry Institute
Technical University Bergakademie Freiberg
Subproject: Cellular materials with zinc matrix
Industrial partner:
BMW AG Landshut plant
Development of design guidelines for the different materials
Determination, design and production of a prototype
Investigation of material application in energy-absorbing profiles (so-called crash absorbers) in the bumper beam
Dennert Poraver GmbH
Optimization of mineral foam granules
Production of component prototype
DST Dräxlmaier Systemtechnik GmbH
Investigation of material behavior at high strain rates (drop tower tests)/li>
Development of design guidelines for the different materials/li>
Determination, design and manufacturing of a prototype
CADFEM GmbH
Implementation of the material laws in FEM software
FEM consulting & support
Grillo Werke AG
Main focus on content:
Development & optimization of zinc foam
Production of test specimens
HZD Havelländische zinc die casting GmbH & Co.KG
Optimization zinc foam
Production of component prototype
HÖRMANN Engineering GmbH
Development & design of component prototype
Development of design guidelines for composite material
Quadrant EPP Nederland B.V.
Production of solid specimens of the matrix material, specimens of the filler-matrix composite (with the support of Poraver) as well as simple structural components (sandwich panels, filled hollow sections, etc.)
Material data for plastic matrix
ZoE Center of Exellance GmbH & Co.KG
Production of solid specimens of the matrix material, specimens of the filler-matrix composite (with the support of Poraver) as well as simple structural components (sandwich panels, filled hollow sections, etc.)
Production of component prototype
Material data for duromer matrix
Data & Facts
Project name | IMVAL – Innovative mineral foam composite applications for lightweight construction |
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Technology field | Lightweight materials, lightweight mechanics, lightweight design, design methodology, mechanics of materials, numerical simulation |
Project duration | 01. August 2003 until 30. April 2007 |
Project volume | 1,5 Mio. EUR |
Funding | 0,8 Mio. EUR |
Support Program | InnoNet, Federal Ministry of Economics and Technology (BMWi) |
Project Promoter | VDI / VDE Innovation + Technik GmbH |