Stability Analysis Of Open Section Steel Columns Strengthened By CFRP Under Axial Compression

Open section steel is often used in steel structure buildings,especially H-section steel and C-section steel.H-section steel belongs to economic section steel,which is Usually as the main load-bearing member,because H-section steel itself has better bending resistance along its strong axis direction;In terms of structure,its upper and lower flanges are not only wide but also parallel to each other,which makes it more and more widely used and developed in large-span and super high buildings due to its advantages of large lateral stiffness and simple structure;C-section steel is often used as the mechanical structure of civil buildings because of its good bending and compression resistance.Due to natural factors and use reasons,the steel structure building itself will cause a certain degree of damage,resulting in a certain impact on the overall structural stability of the building,causing great losses to the interests of the state and the people and public property.With the emergence of new reinforced material CFRP sheet,and CFRP reinforced steel structure has certain advantages,so in recent years,it has gradually become the research object of many scholars,but at present,the steel structure members strengthened by CFRP are mainly focused on circular steel tube or square steel tube,and there is little research on H-shaped or C-shaped steel columns strengthened by CFRP.In view of the lack of research at this stage,this paper mainly carries out the following aspects Research.(1)A total of 26 open section steel columns were established by ABAQUS software,including 13 H-section steel columns and 13 C-section steel columns(including 1unreinforced comparative member and 12 members with different reinforcement methods),and a "solid shell" model was established to simulate the reinforcement of different open section steel columns by CFRP under axial compression.(2)The influence of the number of CFRP layers and the bonding distance(0 mm,50 mm,100 mm and 150 mm)on the ultimate bearing capacity of the strengthened open section steel columns is analyzed.By increasing the number of CFRP layers,the bearing capacity of open section steel columns can be improved.When the angle between the column height and the adjacent CFRP is more than 45 °,the effect of improving the bearing capacity of open section steel columns is better.(3)Based on the establishment of the calculation formula of the stable bearing capacity of steel members after reinforcement,and the comparative analysis of the simulation value and calculation value,using the orthogonal design method,this paperexplores the influence of the bonding distance and the number of CFRP layers on the bearing capacity of two types of steel columns with cross-section,and then deduces the correction coefficient of the formula of the ultimate bearing capacity of H-type and C-type steel columns strengthened by CFRP under the action of axial compression,and gives the axial compression with the correction coefficient The ultimate bearing capacity of H-type and C-type steel columns strengthened with CFRP is calculated.