Modelling, Simulation and Experimental Investigation of a Rammer Compactor Machine

Abstract: This licentiate thesis considers the modelling, simulation and experimental investigation of a rammer compactor machine. The purpose is to develop an efficient and verified method for simulation of rammer compactor machines to be used in the product development process. The experience gained through this work is also intended to be useful for studying other types of dynamic compactor machines. Rammer compactor machines perform impact soil compaction. This is more efficient than static compaction. The machines are often used in places where a high degree of compaction is needed, and where the space for operation is limited. The complexity of this type of machine makes design optimisation through traditional prototype testing impractical. This has pointed to the need for a theoretical model and simulation procedure for predicting the dynamic behaviour of the machine. To be useful for optimisation the theoretical model and simulation procedure must be verified. By concurrently working with theoretical modelling, simulations, experimental verifications, and optimisation an efficient analysis support for product development is achieved. This co-ordination works both ways in an iterative manner: experimental investigations are used to verify theoretical models and simulations; and theoretical models and simulations are used to design good experiments. This Complete Approach concept enables better decisions to be made earlier on in the development process, resulting in a decrease in time-to-market and improved quality. In this thesis, the Complete Approach concept is applied to a rammer soil compactor machine. An introductory iteration is described. The good agreement between theoretical and experimental results indicates that the theoretical model and simulation procedure should prove useful in introductory optimisation studies. The thesis discusses reasons for the remaining discrepancy and suggests improvements in both the theoretical model and the experimental set-up for future iterations.