Konstruktionslösning av slagutmattningsrigg för Volvo Technology AB

Abstract

Impact fatigue testing is an important tool for evaluating the lifespan of a component under real operating conditions. The test involves two components that are subjected to cyclic impacts, commonly up to 1 million cycles with constant impact energy. To ensure reliable results, high accuracy and repeatability in every impact are needed. At Volvo Technology AB, impact fatigue tests are conducted with a custom, in-house constructed test rig. The results are used to verify that gearbox components can withstand cyclic impact loads. The current impact fatigue test rig fails to meet accuracy and repeatability requirements. Because of this, there is a demand for a new, more accurate and flexible impact fatigue test rig that can be used for various components. The purpose of this degree project is to develop a design solution for this test rig. The work was initiated by examining the current solution together with the client, with the aim of identifying customer requirements. A new concept was developed through a structured product development process where different concepts were evaluated and refined using decision matrices. The final concept formed a basis for calculations, which formed the basis for the design process. The impact was simulated in LS-DYNA using realistic CAD models which provided an estimate of the load that the rig needs to withstand. The results showed that extruded aluminum profiles, especially the 60 x 60 mm Profile 12 from Aluflex have sufficient strength to meet the calculated load. The design process was guided by earlier calculations and customer requirements and needs regarding manufacturing and assembling. The result is a complete mechanical design solution, development of a system that counts the number of test cycles and stops the test at the right time is recommended as further development.