Calculation Of Tire/Road Contact Stress Of Asphalt Pavement Based On Envelope Profile

The tire-road contact stress is of great significance for the study of tire-road contact interaction,and has a very important influence on vehicle comfort,safety as well as the service life of roads.The existing stress measurement methods are mainly sensors and other methods.The test equipment is more expensive and has defects such as low precision and unstable performance.Therefore,it is very necessary to establish a reasonable stress calculation model to solve the contact stress of the tire and road.This paper carries out research from two aspects of theoretical analysis and experimental verification.Firstly,considering the real contact characteristics between the tire and the road,the contact mechanism of the tire and road was deeply analyzed,and the envelope profile was proposed to reflect the real contact between the tire and road.The basic theory of Hilbert-Huang Transform(HHT)is introduced in detail,and an envelope profile calculation model based on this theory is proposed to obtain the envelopment of asphalt pavement texture.Secondly,the stress calculation model is established,and the envelope profile data is taken as the input value of the stress calculation model to calculate the normal stress of the contact between the tire and the road surface.Finally,the hand-held laser scanner is used to obtain the texture elevation data of asphalt pavement,and then the pavement envelope profile and contact stress are calculated.The measured values of contact stress were obtained by the tire-road contact stress measurement system,and feasibility of calculating the contact stress by using the contours of the tire-road contact envelope was verified by comparing the calculated stress with the measured stress.The results show that the actual contact between the tire and the road surface is the contact between the asperities on the road surface and the tire surface.In the simplified two-dimensional space,the actual contact between the tire and the road surface can be represented by the envelope line,that is,the envelope profile.The envelope profile obtained by using HHT method is more close to the real contact state of the tire and road.The relative error between the stress value calculated by the envelope profile and the measured value is within the allowable range,which indicates that this method is feasible and provides an effective reference for the study of the tire-road contact stress.