Four-axis Overloaded Flatbed Roll Characteristics

Platform truck is a kind of special heavy transporting vehicle used in iron and steel mills. The four-axle heavy load platform truck (FHLPT) in this article is used to transport high-temperature liquid iron.The essential difference between FHLPT and common heavy vehicle is the former has huge products of inertia because of its special shape. The serious roll motin of the vehicle's body when turning is easy to result in FHLPT' rollover,then the disaster would kill many people and make property loss.Therefore, how to improve the FHLPT's safety and efficiency plays an important role.In view of a FHLPT weighting 230 tons,the multi-axle steering dynamic model is built while the body's products of inertia are taken into accounted, then the roll vibration performance and the best steering method are got.The main contents of the thesis are as follows:1) The lateral balance of FHLPT is analysed using traditional model. The results show that the existing turning model of conventional vehicle can not be used directly.2) Based on the Newton-Euler's method and Lagrange equation, the nonlinear dynamic turning model of a FHLPT which contains four freedoms is built while the body's products of inertia are concerned. Then the special roll vibration performance of the vehicle's body is obtained by model calculation and numeric simulation. The amplitude of roll angle is increased because of the product of inertia, which makes the FHLPT easier to roll over while turning.3) Combined with the tire's dynamic of multi-axle steering, the roll vibration character of a four-axle FHLPT is analysed. The The result shows that the all-wheel steering(AWS) is the optimal mode of turning.4) Taking a kind of FHLPT weighting 230 tons for the experimental study, the responses of roll angle are measured when the vehicle turning in all kinds of velocity and steering radius.the The results were consistent with the actual value.Research results show that The typical inertia matrix reduces the stability of the nonlinear dynamics turning model, so the maximal velocity is limited when turning. And the all-wheel steering method will raise the safety of the vehicle when turning.