Until now, the durability of plastic components has been extremely difficult to assess, considering the variety of influencing factors. This is particularly important for critical safety components, whose failure involves a significant danger potential and subsequent liability risks.
At the "JEC" trade show held from 1 to 4 April in Paris, at its stand U74, hall 1.3, Fraunhofer LBF will present solutions for simulating the service life of components made from plastic and other composite materials.
The number and usage of components made from plastic and composite materials has been growing steadily throughout the last few years. Until now, reliable, material-specific testing methods and rating concepts for these plastic components, enabling an assessment of their expected service life, have not been available. Within the framework of a Wing Project of the German Federal Ministry for Education and Research lead by Robert Bosch GmbH, engineers are currently working on new material technologies. Research scientists at the Fraunhofer Institute for Durability and System Reliability LBF in Darmstadt are developing a simulation method which will enable the reliable assessment of fatigue and ageing of plastic components under various ambient influences. Using specimens made from thermoplastic materials and resembling the actual components, researchers have investigated the behaviour of the materials in laboratory tests, as a function of material, geometry, manufacturing process and various environmental factors (such as temperature, fuel, or oil). These parameters are critical to strength, load-carrying capability and service life of the materials.
The effect of these combined parameters on material fatigue can subsequently be shown in a numerical simulation of the components. "First of all we analyse the vibratory strength of plastic specimens immersed in an oil bath, by introducing cyclic loads", explains Andreas Büter, Head of Department at Fraunhofer LBF. "Depending on the load at which specimen fatigue or fracture occurs, the fatigue strength, i.e. the relationship between the cyclic load applied and the maximum permitted number of vibrations can be calculated." On the basis of the results obtained, a diagram called Wöhler curve is determined by the engineers, which enables a statistical assessment of the fatigue life of a component.
How a fuel rail, for example, will withstand engine vibrations under simultaneous contact with fuel, is simulated on the basis of the results obtained by means of a numerical model of the component. "We calculate the stress and strain occurring in the material at various loads", explains Büter. "We know from experiments the stresses the material can withstand without damage, and at which strains damage occurs. Hence we can assess the service life of plastic components with maximum reliability".
The purpose of the simulation models, which are adapted to the specific material in hand, is to enable designers to take into account ageing processes and the effects of various ambient factors on plastic components at an early stage in the development phase - similar to metal components. This will reduce the cost and time involved in design modifications and adaptation of shape.
Anke Zeidler-Finsel | Fraunhofer Gesellschaft
Intelligent wheelchairs, predictive prostheses
20.12.2017 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA
Jelly with memory – predicting the leveling of com-mercial paints
15.12.2017 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA
An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.
In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...
19.03.2018 | Event News
16.03.2018 | Event News
13.03.2018 | Event News
22.03.2018 | Trade Fair News
22.03.2018 | Earth Sciences
22.03.2018 | Earth Sciences