Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Service Life Simulation on Plastics under the Influence of Aggressive Fluids

01.04.2008
Components in the vehicle engine compartment must withstand high temperatures, mechanical vibration and the effect of aggressive substances such as fuel, brake fluid or engine oil.

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.

Scientific contact at the show:
Dr. Andreas Büter, Julia Hartmann
mobile +49 172 6184202
julia.hartmann@lbf.fraunhofer.de

Anke Zeidler-Finsel | Fraunhofer Gesellschaft
Further information:
http://www.lbf.fhg.de/

More articles from Process Engineering:

nachricht Applying electron beams to 3-D objects
23.09.2016 | Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP

nachricht New process for cell transfection in high-throughput screening
21.03.2016 | Laser Zentrum Hannover e.V.

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First-Ever 3D Printed Excavator Project Advances Large-Scale Additive Manufacturing R&D

Heavy construction machinery is the focus of Oak Ridge National Laboratory’s latest advance in additive manufacturing research. With industry partners and university students, ORNL researchers are designing and producing the world’s first 3D printed excavator, a prototype that will leverage large-scale AM technologies and explore the feasibility of printing with metal alloys.

Increasing the size and speed of metal-based 3D printing techniques, using low-cost alloys like steel and aluminum, could create new industrial applications...

Im Focus: New welding process joins dissimilar sheets better

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of light metals.
Scientists at the University of Stuttgart have now developed two new process variants that will considerably expand the areas of application for friction stir welding.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Stuttgart in patenting and marketing its innovations.

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of...

Im Focus: First quantum photonic circuit with electrically driven light source

Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Paper – Panacea Green Infrastructure?

30.09.2016 | Event News

HLF: From an experiment to an establishment

29.09.2016 | Event News

European Health Forum Gastein 2016 kicks off today

28.09.2016 | Event News

 
Latest News

First-Ever 3D Printed Excavator Project Advances Large-Scale Additive Manufacturing R&D

30.09.2016 | Materials Sciences

New Technique for Finding Weakness in Earth’s Crust

30.09.2016 | Earth Sciences

Cells migrate collectively by intermittent bursts of activity

30.09.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>