Automotive Science and Engineering

---

Car body lightening and crashworthiness are two important objectives of car design. Due to their excellent performance, composite materials are extensively used in the car industries. In addition, reducing the weight of vehicle is effective in decreasing the fuel consumption. Hat shape energy absorber is used in car’s doors for side impact protection. The aim of these numerical models and experimental tests is to unveil some important fact about using composite materials in hat shape energy absorber and also show the effect of orientation angles on the amount of energy absorption. The effects of different orientation angles on crushing behavior of hat shape structure are presented.

---

The main objective of this study is to investigate the vibrational behavior of the crankshaft mechanism of an IC engine operated on motoring mode as a function of the lubricant type, oil temperature. This attempt included instrumenting the engine block with accelerometers to measure horizontal and vertical vibration intensity and running the engine on an electromotor test rig in a specific test procedure namely strip-down method. The experiments were conducted with various cranktrain configurations under different engine speeds, lubricant types and oil temperatures. The results showed that vibration intensity of the cranktrain mechanism increases with increasing engine speed. This vibrations level was maximum in the highest speed. Changes in vertical vibrations caused by crankshaft in different conditions were almost similar to horizontal vibration changes. Also, the engine vibration caused by crankshaft were not affected by the oil type and oil temperature at all engine speeds, and increase in the speed had a very slight effect on this vibration. The engine vibrations due to reciprocating masses increased significantly with the speed rise, and altered by changes in oil temperature. Changing the oil type had almost no effect on vertical vibration caused by the movement of the reciprocating masses at any engine speed. But the horizontal vibration caused by them at a constant oil temperature increased by changing the oil type from 20w50 to 10w40. The experimental results showed that the contribution of the reciprocating masses from the vibrations caused by cranktrain mechanism was much higher than that of the crankshaft.