الفهرس 
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Abstract
ABSTRACT
The submitted work represents a check of single-deck bus structure based on the Regulations of UN-ECE R29 for frontal collision and UN-ECE R66 for rollover evaluation. the first objective represents an evaluation for bus structure during a frontal collision. A lumped mass model is used based on structure members and the experimental tests have been carried out to investigate design parameters on four different samples of members section. The proposed Crash, Danger and Fatal zones are being aimed to get their stiffness and damping as close as possible to that obtained through an Optimization process. Optimization constraints are acceptable deformation and tolerable deceleration limits. On the other hand, a Finite Element (FE) model of a bus frontal structure is developed using ANSYS (Explicit Dynamics) then, it is solved to simulate full-frontal collision. The resulting data from FE model simulation had been used to validate the aforesaid lumped mass model results at impact velocities of 36 and 48 km/hr. Moreover, the Lagrange function has been used to validate the obtained energy absorption. Furthermore, Response Surface Methodology (RSM) optimization technique had been used to optimize the structure members. Unfortunately, whatever changes in the current design are made, the dimensions will not allow the improvement of collision deceleration and intrusion. So, recommendation of increased front crash zone had been concluded.
The second objective is to evaluate a section of the bus structure during rollover test. This evaluation relies on a rollover (FE) Model in ANSYS (Static Structural), in addition to an experimental rollover testing procedure carried out on a physical section of the bus using a tilting platform. Considering the rollover results of the given bus design, there was a fatal problem in the welding of side rails with the roof members as it was concluded through the experimental test. However, Topology Optimization is applied to the modified design which permitted a weight reduction under the same constraints. So, recommendation of reduced bus section weight had been concluded