IKV Logo Portrait

Student paper

Combined testing: Multiaxial material testing of short fiber reinforced thermoplastics

Project work

Learn the injection molding process and the tension-compression-torsion test.
Stuwi-Kombiniert geprüft_Multiaxiale Werkstoffprüfung© IKV
The tensile-compressive-torsional test (left) allows three different material properties to be determined using a tubular specimen geometry (right). The homogeneity of the stress state is ensured by the clamping and the application of forces.

Topic of the work:

Short-fiber-reinforced thermoplastics are characterized by excellent processing properties. Fiber reinforcement can significantly increase mechanical properties such as stiffness and strength, resulting in great potential to increasingly replace metals as a construction material in structural applications. In these fields of application, combined stresses often occur, which change the relevant strength parameters. As a result, high safety factors are often applied when designing components, so that part of the material potential remains unused. Recent developments in the working group enable a material-specific experimental investigation of the strength behavior of short-fiber-reinforced thermoplastics under combined stresses and thus create the basis for improved design practice.

The work is related to this research project:

The work takes up an open scientific question that deals with the failure mechanisms of short-fiber-reinforced plastics under combined stresses. In particular, the varying fiber orientation over the component thickness currently makes it difficult to reliably predict the failure behavior. This results in either premature component failure or material-intensive oversizing. The aim of the work is to investigate the failure experimentally and to create the basis for improved dimensioning.

Objective:

Based on preliminary developments, a prototype of an injection mould was developed that will make it possible in future to achieve a homogeneous, highly oriented fiber orientation distribution in pipe specimens. The prototype of a test procedure that can be used to set any desired stress conditions was also designed in line with this. The aim of your project work is to get to know a new manufacturing and testing concept and to apply it experimentally. For this purpose, pipe test specimens are produced by injection molding. You then carry out the tension-compression-torsion test to induce defined normal and shear stresses using the existing test method. The resulting stress and strain state is determined on the basis of the recorded data.

Your task:

  • Familiarization with the existing injection moulding and testing process
  • Production of pipe specimens by injection molding
  • Testing of pipe specimens in the tension-compression-torsion test
  • Evaluation and interpretation of the test data

Your profile:

  • Natural science or engineering degree (e.g. general mechanical engineering, industrial engineering, materials science, applied polymer science)
  • Independent and quality-conscious way of working
  • Interest in experimental work and scientific data analysis
  • Ideally initial experience in the field of mechanical testing

These are your benefits:

  • Learn scientific work in a motivated team with intensive supervision
  • Participate in the co-development of a new testing methodology and support its transfer to near-series testing with high industrial relevance
  • Build on existing prior experience and expand it in a targeted manner in an experimental environment under intensive supervision
  • Learn the systematic collection, evaluation and interpretation of experimental measurement data

Has this vacancy piqued your interest? Then get in touch with me by e-mail or phone and send me your application documents.