In bone drilling process during the surgical operations, heating increases due to high bone/drill contact friction that damages the bones and soft tissues. The overheating is usually recognized as the temperature rise exceeds 47°C, a critical limit, above which the drilling causes osteonecrosis. In this study, a new driller system is developed to prevent the overheating in orthopedic surgeries. It has a closed-circuit cooling system to reduce the undesired temperature rise during the drilling process. It is also designed and manufactured as a prototype and tested experimentally in vitro by drilling fresh bovine bones using different processing parameters. In the drilling tests, the temperature levels of the bones are measured using thermocouple sensors. Based on the measured results, the driller system provides a valuable temperature reduction around 25 % to prevent necrosis in low spindle speeds (rpm) usually preferred by surgeons. The measured temperatures from the tests of the driller system with a cooling system were compared with the use of regular bone drilling process without cooling. The optimum processing parameters of the new driller system with/without coolant are calculated using the Taguchi method, and the most effective parameter is found as rpm.

In this study, a computer program was developed using Q-Basic programming language to analyze the strength and deformation of a rotating circular stepped shaft. These shafts have a variety of powertransmitting mechanical elements (components), such as pairs of gears, and pulleys that are modeled in 3-D. In addition, force and moment analyses of these elements running on the shafts are examined. Notch sensitivity and stress concentration factors given graphically were formulated using the finite difference method. Furthermore, to select the best rolling-contact bearings, an expert system requiring the knowledge-based technique was employed. The knowledge of the expert system and data of the rolling bearing catalogue were input into the program. To perform the expert system, the LEONARDO software technique was used.

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This study addresses the prediction of the burst pressures and burst failure locations of the vehicle toroidal liquefied petroleum gas (LPG) fuel tanks using both experimental and finite element analysis (FEA) approaches. The experimental burst test investigations were carried out hydrostatically in which the cylinders were internally pressurized with water. The FEA modeling processes of these LPG fuel tanks subjected to incremental internal uniform pressure were performed in the nonlinear field. Two different types of nonlinear models, plane and shell, were developed and evaluated under nonuniform and axisysmmetric boundary conditions. The required actual shell properties including weld zone and shell thickness variations were also investigated and used in the computerized modeling processes. Therefore, the results of the burst pressures and their failure locations were predicted and compared with experimental ones.