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Developing test procedure and design of fixture for dynamic test of road ambulances

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2019
Kaya, Sinan
The number of traffic accidents involving road ambulances is increasing. This situation increases the risk of death and injury of the patients and healthcare workers transported in the patient transport cabin of the road ambulances. Therefore, providing a safer environment for these occupants has become important. Medical devices, drawers, stretcher systems used in the road ambulances should be secured to avoid endangering safety of the occupants. The conformity of the fixing systems designed for this purpose must be verified by performing the 10 g tests of ambulance patient transport cabin in a sled test facility as required by EN 1789+A2 standard. The rules described in the standard cause some ambiguities during the evaluation of the test results. In this study, a new test procedure has been proposed in order to prepare the test sample properly, conduct tests and evaluate test results for the road ambulance tests. According to EN 1789+A2 standard, the 10 g tests are performed for five different directions (front, back, left, right, vertical). In METU-BILTIR Center Vehicle Safety Unit, the fixtures are used to fasten the test sample (i.e. ambulance cabin) to the sled during the tests. Dynamic analysis of the test fixture used for vertical direction has been performed by using Finite Element Analysis (FEA) Software Ls-DYNA. The results of FEA and deformations of the currently used test fixture during the tests have been observed and compared. It has been evaluated that the design of the fixture for the vertical direction test should be improved. Two completely new test fixtures and one with modifications on the currently used fixture are designed and FEA for these have been realized. It has been seen that these three alternative test fixtures provide advantages over the currently used fixture by decreasing plastic deformation.