Study of mechanic properties changes in distorted chassis in automotive sector

Thesis Type: Postgraduate

Institution Of The Thesis: Gazi Üniversitesi, Fen Bilimleri Enstitüsü, Turkey

Approval Date: 2013




In the year 2010, 1.104.388 traffic accidents took place, 4.045 people died and 211.496 people were injured in these accidents. Our country is the first in ranking among Europe and among the 10 in the World. In 2010, 25000 cars were discarded from traffic (cars which can not be used because more than 60% of them are damaged) and other cars were repaired and used again. We are going to do our study on the chassis of the cars which are usually damaged in most of the accidents. The search of manufacturing process of a chassis and the mechanical changes taking place within chassis in an accident are aimed. The samples were prepared in three different ways as; original panel, cold rectified panel after deformed and hot rectified panel after deformed. Samples were compared with each other by means of; tension test, crash and notch test, fatigue test and hardness test. As a result of the tension test it was seen that three original panels came off on the 26,877mm; cold rectified samples came off on 17,317mm; the most different changes were seen in the hot rectified samples. First sample came off on 8mm, second sample came off on 13mm, third sample came off on 18mm and on average 13,250mm. As a result of the crash and notch test in which the 5 test samples were taken from the original panel, it was identified that they came off on 26,6 joule, in 5 samples taken from cold rectified panel it came of on 24,6 joule, in 5 samples taken form hot rectified panel it came off 24,4 joule. In the hardness measurement test which was carried out in 9 different assessment point, it was identified that hardness is 112,2 hrb in original panel, 111hrb in cold rectified panel and 50,3 hrb in hot rectified panel. As a result of all the tests carried out, it was seen that chassis undergo a mechanical change whether they are cold or hot rectified and they have serious changes in their structure. These changes are especially remarkable in hot rectified panels.