The strength, strength correction, and axial tension and compression members of steel structure should adopt the strength of thick members; especially the single angle strength correction and single-sided butt weld joint should be connected without backing plate (in the inspection strip and abdominal inspection pole frame building, single angle truss structure)

              The net section method is used to calculate the deformation, stability, shear strength, wool section, bending, tensile and compressive strength.

              The calculation of advance arch: the difference between the two methods of improving appearance and service conditions and improving appearance conditions;

              In the calculation of bending strength of beam, the plastic part should pay attention to the width and thickness ratio coefficient of flange free overhanging, and the ratio coefficient should be controlled within a certain range; the expression method of H-beam (total height * width * total flange thickness × flange thickness) is the height of digital steel.

              The calculation point of transfer stress shall be the edge of the calculated height of beam web height.In the calculation of local compression, if there are stiffeners on the action point of concentrated load, the local compressive stress cannot be checked.Therefore, the local pressure should be 0.

              Calculation of beams: strength, overall stability and local stability (calculation of webs and stiffeners (calculation of transverse, longitudinal, short direction and web points)) (internal force, general height thickness ratio and critical stress).

              Considering the post buckling strength calculation of composite beam webs, the full section of the beam section moment of resistance is effectively determined, that is, the maximum moment of inertia.

               Attention should be paid to the calculation and calculation of friction type high-strength bolt 9, axial compressive strength (at the same time, attention should be paid to the influence of net section); attention should be paid to the calculation of uniaxial symmetrical section, which should adopt the length diameter ratio and corresponding calculation height, axial compression stability (supporting role); (local stability calculation of flange and web).For the local stability mismatch of Web calculation, the strength and stability of members can be calculated by adding longitudinal stiffeners or taking effective network part (only considering the connection of flange and web 20tw, that is, considering the post buckling strength of Web), the full section is still used for the calculation of component strength and stability; at the same time, attention should be paid to the calculation of stability coefficient and stability of members with different bending and compression.The constant compression coefficient is mainly controlled by the control part and the ratio of length to diameter (pay attention to the influence of plate thickness on the class judgment section), the simplified calculation formula of bending stability constant coefficient and corresponding correction.

               10Axial compression, lattice structure calculation, similar type and solid solid axis calculation, while the virtual axis is used to calculate the equivalent slenderness ratio; batten plate (axial compression, calculation of linear stiffness and joint), the calculation of slenderness ratio components (the connection mode and the influence of double limb body on welding or bolt in the calculation of split limb length) and the calculation of component around the virtual axis; and the stiffness requirements of cable batten plate.The section with the same linear stiffness of batten plate is 6 times larger than that of column;

               The double angle steel or double groove steel member is composed of filler plate, which can be calculated according to the actual web member.However, the distance between packing plates shall meet the requirements.The distance between the supporting points on both sides of the filling board should not be less than 2, while the stretching 80i and the radius of my split limb should not be less than 2.

               Calculation of 14 member length: truss and frame structure (pay attention to the correction of swing hinge column and corresponding modified distal bundle), the difference between supports is not supported, the stiffness calculation of axial compression fixed beam, and the far end of connection); the calculation of supporting length of strong axis X axis is reduced, and the weak axis is Y axis direction.In the roof truss, attention should be paid to the effective length corresponding to the strong axis (x axis) and weak axis (Y axis) of T-section, and the influence of supporting plane.Generally greater than x, Y direction, attention should be paid to the bending and bending calculation of bent column and frame column, whether the corresponding bending moment in and out of plane has support, and the transverse displacement and calculation length without corresponding effect, such as the frame structure, is usually supported in the longitudinal and lateral swing, and the strength checking calculation of the support frame: pay attention to the support angle level of the unit.

               It should be noted that the calculation of welding seam (vertical force enhancement coefficient in the direction of weld) and side seam (calculation length should not exceed 60hf) are different.The weld length shall not be less than 8hf and 40mm; in the bending moment butt weld, the effective moment of inertia of the weld shall not be deducted in arc plate welding