Analysis of the superstructure of a designed bus in accordance with regulations ECE R 66

Compliance with certain technical standards and requirements in designing and producing vehicles is necessary for vehicle manufacturers. Within this scope, Regulation ECE R 66 - Large Passenger Vehicles - The Strength of the Superstructures - was studied in this investigation regarding the "Motor Vehicles Type Approval Directive". A finite element model of the superstructure of a designed bus was created and analysed according to ECE R 66 requirements and the results were compared with the test results of a section of the bus superstructure

Experimental analysis of the friction coefficient effect of the zinc‐lamella coated fasteners on bolt preload and tightening moment

Basic parameters of the bolt-nut joints, which are ones of the most important elements of assembly processes, are the torque, bolt preload and friction coefficients between bolt and nut interfaces. In bolted joints tightened with torque and angle-controlled method, friction coefficients of the fasteners are highly significant because they affect final torque and bolt preload values directly, creating a large uncertainty in regard to meet the minimum requirements on preloads considering the safety of joints and further systems, in case of this study, the vehicles being assembled. Also, the range of the lower and upper limits of friction coefficients of the coated fasteners affect process quality considerably in bolted joints tightened with torque and angle-controlled technique. In this study, the effect of the friction coefficients on the bolt preload and final torque values in the vehicle chassis joints, which are created using torque and angle-controlled tightening, were investigated experimentally. Therefore, bolt specimens which have both low and high friction coefficients, were tightened by the torque and angle-controlled tightening method especially using high angle torque parameters on the vehicle chassis test bench. The torque and preload values obtained have been compared to each other and correlated in terms of the friction coefficients occurred