Analysis Of Mechanical Properties On Cargo Constraint System Of Truck Rollover

With the increase in volume of cargo,lots of countries have taken more and more attention to the safety of road transport, so the requirement of tie down is more and more stricter.But in our country there are not operation specification of tie down,it would embarrass the application of tie down.Before you institute the operation specification,you must analyse the property of the tie down when truck accidents happen.Rollover accident is one of the truck accidents,it is especially violent and cause greater damage and injury than other accident,so this paper analyse the property of the tie down when rollover accident happens, educe the minimum number of tie down to prevent cargo apart from truck,provide the foundation to institute operation specification.This paper set up a system which is made of truck,cargo and tie down.To upbuild the physics model of the system,this paper select EQ1156W3 truck and two TD50B tie downs in accordance to the mass of the cargo and the American standard as the research object.Use lateral acceleration as vehicle-cargo-tie down system rollover index,and calculate the rollover threshold.In order to evaluate the vehicle rollover performance by less parameters,constitute mathematic model of rigid vehicle-cargo-tie down system,then get the relationship between the mass of cargo and rollover threshold.Based on above analysis,constitute mathematic model of suspended vehicle-cargo-tie down system to get the rollover threshold,and then constitute mechanical model of cargo-vehicle,get the minimun number of tie downs to prevent cargo apart from vehicle.To analyse the mechanical properties of tie downs during the vehicle rollover,this paper takes two steps to constitute the rollover model of vehicle-cargo-restraint system.Firstly,when the inside wheel does not leave the road,the roll angle is ranged from 0°to 11.6°,build the five-freedom dynamic model of the system,simulate it by Matlab/simulink to obtain the maximum elongation of the tie down;Secondly,when the inside wheel leaves the road,the roll angle is ranged from 11.6°to 90°,build the six-freedom dynamic model of the system,simulate it by Matlab/simulink to obtain the maximum elongation of the tie down.Based on above simulations,establish weather the tie downs meet the requirement,get the minimun number of tie downs to prevent cargo apart from vehicle.Based on above calculations and simulations,get the minimun number of tie downs to prevent cargo apart from vehicle when vehicle rollover accident happens.According to the American standard,set up a new formula used for operation of tie down.