1.0.1 This code was formulated with a view to implementing the national technical and economic policies and living up to state-of-the-art technologies, economy and rationality, safety and usability as well as ensuring quality in the design and construction of cold-formed thin-wall steel structure.
1.0.2 This code is applicable to design and construction of cold-formed thin-wall steel structure of construction engineering.
1.0.3 This code does not cover the special requirements of bearing structure directly bearing dynamic load and cold-formed thin-wall steel structure suffering deep erosion action.
1.0.4 The design principle of this code is established according to the current national standard "Unified Standard for Reliability Design of Building Structures" GB50068.
1.0.5 The design of cold-formed thin-wall steel structure shall be carried out combining engineering practice, reasonably selecting material, structure scheme and structure measure, assuring structure meeting strength, stability and rigidity requirements in transportation, installation and application process, and meeting fire protection and corrosion protection requirements.
1.0.6 Except for those requirements stipulated in this code, those in the current relevant national standards shall also be complied with for the engineering and construction of cold-formed thin-wall steel structure.
2 Terms and Symbols
2.1 Terms
2.2.1 Elements
It refers to the plane plate part between two adjacent longitudinal sides of thin-wall formed-steel member.
2.1.2 Stiffened elements
It refers to the elements that two longitudinal sides are connected with other elements.
2.1.3 Partial1y stiffened elements
It refers to the elements that one longitudinal edge is connected with other elements and another longitudinal edge is rolled and stiffened by satisfactory edge.
2.1.4 Unstiffened elements
It refers to the elements that one longitudinal edge is connected with other elements and another longitudinal edge is free.
2.1.5 Uniform1y compressed elements
It refers to the elements bearing even axes pressure action.
2.1.6 Non-uniformly compressed elements
It refers to the elements bearing linear nonuniform distribution stress action.
2.1.7 Sub-elements
It refers to the elements that one longitudinal edge is connected with other elements, another longitudinal edge is connected with satisfactory middle stiffened rib or two longitudinal edges are connected with satisfactory middle stiffened rib.
2.1.8 Width-to-thickness ratio
It refers to the ratio of elements width and thickness.
2.1.9 Effective width-to-thickness ratio
It refers to the ratio of reduced elements width and thickness after reducing elements width so as to simplify calculation when considering compressing elements to utilize flexed strength.
2.1.10 Effect of cold forming
It refers to the phenomena of steel performance change caused by cold forming.
2.1.11 Stressed skin action
It refers to the ability of resisting shear deformation in plate plane for formed steel reliably connected with support member.
2.1.12 Flare groove welds
It refers to the welds that connecting round angle and round angle or round angle and plane plate gap.
2.2 Symbols
2.2.1 Action and action effect
B——the bimoment;
F——the concentrated load;
M——the bending moment;
N——the axial force;
Nt——the tension bore by one connector;
Nv——the shear force bore by one connector;
P——the pretension of high-strength bolt;
V——the shear force
2.2.2 Calculation index
E——the elasticity modulus of steel;
G——the shear modulus of steel;
——the shear bearing capacity design value of each weld spot of resistance spot welding;
——the tensile bearing capacity design value of one bolt;
——the shear bearing capacity design value of one bolt;
——the compressive bearing capacity design value of one bolt;
