Analysis Of Interface Stress And Failure Of Reinforced Concrete Beam Strengthened With Steel Plate Under Static And Dynamic Loads

Bonding interface is the key to the reinforcement effect.Previous studies have focused on the interface stress analysis of steel reinforced concrete under static load.However,in practical engineering,the reinforced concrete beams are subjected to dynamic loads such as wind load,seismic load,or mechanical vibration,in addition to their own static loads.Therefore,the study on the interface stress distribution characteristics,influencing factors and failure modes of reinforced concrete beams strengthened with steel plates under static and dynamic loads is of practical significance for practical engineering design and safety assessment.In this paper,the numerical simulation analysis of reinforced concrete beams strengthened with steel plates under static and dynamic loads is carried out.In the model,steel and concrete adopt "separated" modeling,cementation layer solid element is used to describe,between concrete and colloid elements,steel plate and colloid elements are used of common nodes to simulate the actual loading process of displacement and deformation coordination.The main contents of this paper include: 1)interface stress distribution characteristics of concrete beams strengthened with bonded steel plates under static and dynamic loads;2)the size of the structure of the original static load,the size of the original structure stiffness,the size of the vibration load frequency,such as this factors influence to the interfacial stress;3)the strain evolution characteristics of after strengthening reinforced concrete beam under dynamic and static combined loads,the evolution process of steel plate stress concentration,the time history of the effective stress of the concrete element,colloid elements and steel plate elements on the reinforced beam;4)comparative analysis of vibration modes of reinforced concrete beams before and after steel bonded reinforcement.The results show that the reinforced concrete beam after steel plate strengthed under dynamic-static loads,the adhesive layer interface stress on both ends of the steel plate appear stress concentration phenomenon,in slightly away from the end plate interface stress appears fluctuating phenomenon,with the decrease of the distance to the beam cross,the interface stress decreases quickly,in the position of beam cross the stress is smaller than the stress at both ends of the steel plate;The reinforced concrete beam after steel plate strengthed under dynamic-static loads,the structure original static load,the original structure stiffness and vibration frequency of the load in a certain range,the greater the interface stress concentration phenomenon is more obvious;The stick steel reinforcement concrete beam under dynamic-static loading failure modes is the beam bottom concrete elements failure,so as to make the colloid and steel plate from stripping off the beam.which eventually leads to the failure of the strengthened beam.The first 10 natural frequencies of beams strengthened by bonded steel are increased to a certain degree.