Experimental research of effectiveness of brakes in passenger cars under selected conditions

The subject of the considerations presented herein is experimental research of effectiveness of disc brakes on various road surfaces in both dry and wet road conditions on the example of a passenger car equipped with different kinds of tyres. The factors affecting the length of the braking distance of a passenger car were described on the basis of which braking delays were measured for three selected tyre types with a different tread depth for three vehicle speeds of 50 km/h, 70 km/h and 100 km/h in order to determine how selected factors affect the braking distance of the vehicle. The experiments were conducted on a dry asphalt surface, a wet asphalt surface contaminated with sand as well as for comparison purposes, on a wet and dry concrete surface. The tests were conducted with the use of mid-range vehicles equipped with disc brakes with a diameter of 288 mm, 312 mm and 320 mm. The author hereof complied an analysis of the results for various combinations of discs, tyres, surfaces and vehicle speeds. The experiments demonstrated that the difference in the length of the braking distance between a dry and wet surface amounts to 1.87 m for 50 km/h, 3.18 m for 70 km/h and 4.97 m for 100 km/h. On the basis of the conducted experiments it might be concluded that braking is more efficient on an asphalt surface. With each type of the analysed brake discs, the distance needed stop the tested vehicle on a concrete surface was longer.