Experimental Study On Shear Lag Effect On Lab Steel Plate Joints With Longitudianl Welds

Welded joint lap joints are widely used in engineering practice.In practical applications,there are many situations in weld length and spacing.The change of weld length and spacing and eccentricity will produce shear lag effect,affecting the actual cross section.Efficiency,this mechanism of influence requires sufficient theoretical analysis,finite element simulation,experimental research,and engineering practice.In the specification of ANSI/AISC 360-16,a new formula is introduced for the calculation of the section efficiency of the welded joint of the lap joint.This formula is based on theoretical analysis and finite element simulation,and lacks test verification.The domestic specification also lacks the relevant design of the axial joint of the lap joint.Therefore,this paper studies the effect of steel plate lap joint joint structure on shear lag effect.The main research contents are as follows:(1)The mechanical properties of the welded joint lap joint under axial tension are studied.The weld(balance,unbalance)and spacing are analyzed by the load-displacement relationship curve and the load-strain relationship curve of the test piece.Effect of shear lag effect caused by test parameters such as spacing on the cross-section efficiency of lap joints.(2)The test results show that the load-displacement curve of the specimen during axial stretching basically includes the elastic section,the yield section and the reinforcement section.The different structures of the lap joint have a great influence on the bearing capacity;the stress of the base metal near the weld is higher,and the lap joint The welded joints are prone to breakage of key sections,and the specimens have poor deformability and fail to exert good deformation properties.The strain gauges with critical sections close to the welds grow faster,entering the yielding and strengthening stages ahead of time.Difference;the bearing capacity of the isometric and unbalance weld specimens is not much different from that of the fracture mode.When the width of the test piece is narrow,the weld bead is not bent.(3)Through the comparative analysis of the calculated values of the test data and the normative calculation formula,the parameter analysis is carried out to obtain the influence law of the weld length and the shear force hysteresis effect on the shear lagphenomenon of the lap joint steel plate.Can the formula accurately reflect the actual cross section of the component effectiveness.By comparing the calculated value with the experimental value,the agreement between the two is better,and the accuracy of the standard formula is verified;based on the test results,relevant design suggestions are given.