Force Analysis And Delamination Extension Mechanism For Steel Bridge Deck Pavement Structures At Ambient Temperature

With the rapid development of long-span steel bridge,the study of steel bridge deck pavements had become hot topics with technical researchers.There are two main types of loads on the long-span steel bridge deck pavements.One of them is the vehicle load,the other one is the environment temperature load.In summer,the steel bridge deck pavements are used under the extremely high temperature for long time,which will produce extremely adverse effect.At the same time,as the bonded layer is the weakest position of the steel bridge deck pavement structures,bond delaminating failure is one of the most common types of damage in the steel bridge deck pavements within the early destroial period.Using the thermal-stress coupling analysis,contact element and life&death element analysis function in the ANSYS finite element software,the temperature stresses for the steel bridge deck pavement structures with the effect of the bonded layer are discussed under the high temperature load.Then,the effect of the delamination failure on the temperature stresses for the steel bridge deck pavement structures are analyzed and the delamination extension mechanism are revealed.The main contents contain as follows:1.The influences of the steel bridge deck structure parameters on the temperature stresses are analyzed.The main structure parameters include the thickness and elastic modulus of the bonded layer and the thickness and elastic modulus of the pavement layer.Firstly,the influence of a single parameter change on the temperature stresses is studied.Secondly,considering the common role of four parameters,4 factors 5 levels of numerical experiment is conducted.Then,according to the results of numerical experiments,the fitted formula for the temperature stress is obtained.And the feasibility and the rationality of the formula are verified.2.The influences of the delamination failure on the temperature stress of the steel bridge deck pavement structures are analyzed.The contact element and life&death element analysis function in ANSYS finite element software are used to3.simulate the bonding layer destruction of the steel bridge deck pavement structure.Firstly,by considering several different forms of the delamination,their effects on the temperature stress are discussed.Then,the influences of the different position and area of the delamination on the temperature stress are investigated.In the end,the stress nephogram is taken to show intuitively the effect of the delamination failure on the temperature stress.4.The delamination extension of the steel bridge deck pavement structures under high temperature load is revealed.Setting a limit stress in the ANSYS finite element software,if the elements' stress is more than the limit stress,they will be killed.The delanination extension mechanism of the steel bridge deck pavement structures under the different forms of the delamination are revealed,and the influence of delamination extension on the temperature stress and delamination extension rate are showed.