The Research On The Character And Design Method Of Gabled Frames Light-steel Structure Joints

In this paper, the general situation and virtue or disadvantage about light-steel structure abroad and at home is concluded systematically. The design method ,steel characteristic in the connection, the bolt strength ,welding line characteristic and the joint connection model about gabled frames structure is introduced . The factors, such as end -plate thickness, bolt's types , beam and column ' flank ,that can effect on the joint rigidity and moment capability, are analyzed.The two kinds of joint connection half-rigidity characteristic about gabled frames are discussed. The criterion among rigid connection, zero rigidity connection, half rigidity connection is determined; the joint's moment and rotation angle curve is analyzed; The calculation method about joint initial rigidity is brought forward; The ultimate moment's calculation formula is deduced; the result calculated by the formulas is compared to one calculated by the norm's formulas.The experiment about gabled frames joint's capability is performed . The experiment procedure and analysis result about exteriorly extended end-plate connection with high strength bolt are introduced primarily; each sample's dimension is given . The adding load equipment ,measuring apparatus placed, measuring point established is detailed .Adding load measure load and M- curve is produced ; The single span gabled frames horizontal displacement formula is deduced when the horizontal concentrated force is applied to it.According to the above formula, the initial rigidity and ultimate moment is calculated by developed program to several kinds of gabled frames end-plate connection joint with different types (such as end-plate connection horizontally placed , vertically placed and inclinedly placed), different end-plate thickness, different bolt diameter. The different result is compared with different end-plate thickness, the different force arm in joints, different bolt diameters and strength grades.The frames deflection and moment at the center point of the span about different kinds of gabled frames, different highness and rigid connection column feet is got when horizontal force at the top of a column and equal linear load through a beam is applied.From the analysis ,some suggestion about joint rigidity design is putforward : 1.Joint initial rigidity can be enhanced within the limited range when to increase end-plate thickness; 2.the rigidity and ultimate moment can be enhanced obviously when to adopt the beam with inclined section or to add axilla at the connections between beam and column; 3.withm the permissive construction condition, exteriorly extended end-plate inclinedly placed is suggested to be applied firstly; 4.when the rate of joint rigidity to beam rigidity, that is called ,is less than 0.1,the joints can be regarded as zero-rigidity joints; on the other hand, if is more than 26,it is rigid connection joints.