Development of a Method to Determine the Influence of Rubber Components in Dynamic Simulations

Sammanfattning: In order to make sure that an engine can withstand the vibration loads, while the weight is kept as low as possible, some components on the engine are made of rubber. The stiffness of these rubber components are several orders of magnitude lower than the surrounding metal components, and the inclusion of rubber components affects the dynamic behaviour of the engine. Rubber also exhibit behaviours that makes it complicated to represent when performing the dynamic simulations required to determine the fatigue life of the engine components. The material is hyperelastic, and the stiffness is dependant on frequency and excitation amplitude. This master’s thesis has studied the GW/Retarder coolant pipe installation on a Scania engine, and how the dynamic behaviour of the pipes changes with the inclusion of rubber hoses. The purpose has been to identify the most efficient way to include the influence of the rubber hoses in frequency domain simulations with low stretch amplitudes. Several different modelling approaches have been tested, in order to determine the most suitable method for including the influence of the rubber hoses on the dynamic properties.  In order to verify the results from the simulations, data from testing on a shaker table has been used. In the end an approach is suggested for use in modal based frequency domain simulations. The conclusion is based on simulations on the full engine setup, along with tests on a different configuration in order to generalise the results for use in different situations.