1. Strength: the ability of the cross-section material or connection of the component to resist damage. Strength calculation is a calculation to prevent structural members or connections from being damaged due to excessive material strength

2. Bearing capacity: the maximum internal force that a structure or component can withstand without being damaged due to factors such as strength, stability or fatigue; or the maximum internal force when plastic analysis forms a failure mechanism; or the internal force when it reaches the deformation suitable for continued bearing

3. Brittle fracture: generally refers to the brittle fracture that occurs suddenly in the steel structure without warning plastic deformation under tensile stress.

4. Strength standard value: steel building yield point (yield strength) or tensile strength specified by national standards

5. Effective width: when calculating the strength and stability of the section, the effective width of the plate in advance

6. Calculated length: the geometric length of the component between its effective constraint points is multiplied by the equivalent length that takes into account the deformation of the rod end and the coefficient of the situation, so as to calculate the slenderness ratio of the component. The length of the weld used when calculating the connection strength of the weld

7. Overall stability: Assessment of whether the entire structure or component can buckle or lose stability under external action

8. Buckling: The rod or plate is suddenly deformed and loses stability due to the independent or combined action of axial pressure, bending moment, and shear force, which is inconsistent with the original force state.

9. Supporting force: at the lateral support provided for the free length of the intervening compression member (or the compression flange of the member), the force required to be applied in the buckling direction of the supported member (or the compression flange of the member) The lateral force at the shear center of the member (or the member's compression flange)

10. Combined component: a component composed of more than one steel plate (or section steel) connected to each other, such as an I-shaped cross-section or a box-shaped cross-section composite beam or column