To meet the new demand the automotive industry must be able to effectively design lighter structures leveraging structural plastics and composite materials.
In the automotive industry, increased customer interest in electric and greener mobility and heavy pressure to reduce CO2 emission have moved light weighting to the forefront of the automotive thought process.
To effectively design lighter structures, automotive engineers must deal with the unique challenges associated with simulating structural plastic components.
The behavior and performance of these plastic parts is directly related to the local fiber orientation and the resulting anisotropic material properties which varry at every point in the part. These local fiber orientations are a function of the injection molding process and are what drive the material to have a unique stiffness and failure stress/strain at every location in the part.
In order to accurately predict the stiffness and failure performance of structural plastic parts, the materials anisotropy, nonlinearities, strain rate dependencies and local fiber orientations must be taken into account. Otherwise surprise failures or missed targets during validation testing can lead to cost time and money.Solution
e-Xstream has the expertise and tools that the automotive industry needs to design the next generation of lightweight vehicles that further utilize composite and structural plastics.
Using Digimat in the design process when transitioning from metal to plastics or just further optimizing your existing parts can yield weight savings up to 40% and cost savings up to 20% while maintaining the risk at acceptable levels. Digimat is relied upon by major Material suppliers, Tier1s and OEMs worldwide.Benefits
Digimat enables you to:
- Choose the optimal material for your part
- Design with confidence and increase the accuracy of your analysis
- Take into account the local fiber orientations from injection molding or draping and their effect on the material response.
- Reduce part weight - thus meeting CO2 & CAFE regulations
- Save time and money by eliminating costly late-stage tooling changes
Integrated crash pads allow weight and cost reductions. Setting the absorption behavior is only possible through a rigorous composite modeling. An integrated structural analysis with Digimat clearly reveals those benefits.Digimat is strongly coupled to:
-Sandro Wartzack, Head of Simulation.
- Major nonlinear FEA software (Nastran, Marc, Abaqus, ANSYS, LS-DYNA, PAM-CRASH and SAMCEF)
- Injection Molding software (Moldflow, SigmaSoft, Moldex3, REM3D)
- Short fiber Reinforced Plastics: Technical front end carrier, Air intake manifold, Clutch pedals, etc.
- Long fiber Reinforced Plastic: Engine mount, front end carrier, etc.
- Continuous fiber (UD-, woven-, braided composites, etc.): Body-in-white structures, Shock absorbers, Vessels, etc.
- Rubber (Fluid transfer hoses, Anti-vibration systems, Truck tires, etc. )
- Shape stability (part warpage induced by temperature variation)
- Structural stiffness
- Vibration frequencies and modes (NVH)
- Fatigue under cyclic loading
- Failure under quasi-static loading
- Failure under crash loading
- Progressive failure
- Long term behavior (stress relaxation and creep)
- Weight reduction
Trelleborg's innovative engine mount has been designed in short fiber reinforced plastic. Trelleborg performed coupled analyses of the injection molded part using Digimat to investigate of stiffness, failure, crash and fatigue - while taking into account the heterogeneous field of fiber orientation. Digimat's technology has allowed to define an optimized lightweight shape respecting the different objectives in terms of stiffness, strength and lifetime performances with a good level of correlation compared to the experimental tests. A total mass of 710g, which represents 40% of its initial weight, has been saved, as well as a 15% of cost reduction.
The flap, mounted on the fan system, is submitted to vibrational solicitations. Digimat technology for short fiber reinforced plastics, enabled an accurate simulation of its modal behavior. The use of Digimat multi-scale material model in the coupled FE analysis drives to a reduction of the error from more than 14% with an isotropic definition of the material to less than 5% compared to the experimental modal basis.
The simulated performances on the front end carrier are the stiffness under static load and the identification of the modal basis. The results of the simulations compared to the experimental tests, shows much more accuracy than the usual isotropic method. Furthermore, with the help of Digimat, the cost had been significantly reduced, as well as the number of experimental tests has been minimized.
Solvay's MMI TECHNYL® Design is the application of the technology to re-design an all-steel metal seat pan to a multifunctional injected seat pan. The added value of predictive modelling with an integrative simulation approach was demonstrated. Thanks to Digimat local material behavior and failure criteria, MMI Technyl® Design was the only method that allowed to capture the right chronology of all failure events in the here presented study. While keeping the same functionality, MMI new design achieved a 40% mass reduction along with a 50% parts reduction (including screws and rivets), showing once again how an optimized composite product can deliver outstanding weight and cost performance.
Digimat platform has been applied on the front crash simulation of a bumper beam made in short fiber reinforced plastic. On the accuracy side, an elastic viscoplastic material model has been combined with the fiber orientation field obtained previously by the injection simulation to simulate the front crash at 2 different levels: the part level and the full car level. On the CPU time side, the use of the hybrid calculation mode on Digimat in addition to an optimization of the FE job setting has led to show this advanced multi-scale technology is fully applicable in the automotive industry taking into account its constraints in terms of development timelines.