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Balancing a rotating machine is a vital step towards ensuring it will operate reliably and safely. To achieve this condition monitoring is an important aspect for early faulty detection and it can also result in the improvement of the operational continuity and equipment safety. Imbalance itself, is a common problem in rotating machinery and it can lead to poor or even dangerous vibration levels. And, for example, it is also well known that misalignment can lead to bearing defects. So, in order to overcome these problems many balancing techniques have been developed that are largely based on measured vibration data using accelerometers attached to the faulty device. The three-point method is well known as a basic phase-less technique; this method has been used for balancing equipment and is widely regarded as an industry standard technique. In this work we avoid placing sensors on the device under investigation. This is achieved by utilizing a microphone method located in the nearfield of the investigated device. By comparing the traditional vibration technique with the acoustic contact-less method we can demonstrate the method’s remarkable accuracy. Finally, the experimental results show that there is a similar trend between both the vibration and acoustical responses of the machine, and it is proven that it is possible to balance a rotating machine by just utilizing the acoustical response. This is a contactless method and an innovation in machine-dynamics condition monitoring.

In transition from concept design to detail design, designers and engineers need to find specific materials to optimize performance of the systems. The large number of materials and the wide range of manufacturing processes cause engineers always to seek new materials selection methods. In this research work a new method so called QFD method, which employs materials indices, is introduced. The method enjoys a combination of Ashby’s materials selection concepts with the Quality Function Deployment (QFD) tool. The QFD method, which is modified here to fit the materials selection field, provides the designer with the required weighting factors for the material indices. Incorporation of House of Quality makes it possible to add the effects of the interrelationship of the material indices to the calculation of the required weighting factors. Also, considering the material indices would preserve the generality and quality of the results. The results show that the method can provide comparable outputs to the existing methods. Also, the results prove that considering materials selection methods like MDL and Z-transformation which employ material properties instead of material indices would not adversely affect the results. Though, some differences could be noticed and also the QFD is capable of analyzing much more complicated problems.