Q:What impact does the thickness error of galvanized angle steel have on the bearing capacity calculation?
A:Deviation between design value and actual value: When the negative thickness tolerance exceeds the allowable range of the specification, the actual bearing capacity may be lower than the design value, resulting in partial failure or even overall damage of the structure (such as fracture of steel truss members and collapse of brackets).
Specifications limit tolerances: When designing, the bearing capacity must be verified according to the minimum thickness allowed by the specification (such as using the nominal thickness minus the maximum negative tolerance) to ensure safety redundancy.
Q:What impact does the thickness error of galvanized angle steel have on structural stability?
A:Buckling risk of compression members
Consequences of insufficient thickness: The stability of compression angle steel (such as columns and supports) is closely related to the moment of inertia of the section (proportional to the cube of the thickness). Negative thickness tolerance will reduce the moment of inertia, making the member more susceptible to bending or torsional buckling.
Stiffness and deformation control
Deflection exceeds the limit: The stiffness (measured by deflection) of bending members (such as purlins and brackets) is related to the thickness. Insufficient thickness will cause excessive deformation of the structure, affecting the use function (such as roof leaks and wall cracks).
Q:What impact does the thickness error of galvanized angle steel have on welding and connection performance?
A:1. Weld quality and strength
Insufficient groove depth: When welding thick plates, if the actual thickness is less than the design value, the groove depth may not meet the penetration requirements, resulting in incomplete penetration defects and reduced weld shear strength.
Welding stress concentration: Uneven thickness (such as tolerance fluctuations) will lead to uneven welding heat input, increase welding deformation and residual stress, and may cause cracks (especially high-strength materials such as low-alloy steel).
2. Bolt connection reliability
Insufficient bolt hole filling: Negative tolerance of angle steel thickness may cause the bolt gasket to not fit tightly with the component surface, reduce the connection stiffness, and easily loosen or slip under dynamic loads (such as earthquakes and wind loads).
Q:What impact does the thickness error of galvanized angle steel have on the durability of the material?
A:Correlation of galvanized layer thickness
Hot-dip galvanizing process: Steel thickness affects the amount of galvanized layer adhesion (usually when the thickness is ≥5mm, the galvanized layer is ≥85μm; when the thickness is <5mm, ≥65μm). If the actual thickness is thinner, the galvanized layer thickness may not meet the standard, accelerating the corrosion of the steel.
Cross-section weakening in corrosive environments
Long-term corrosion loss: In humid, acidic and alkaline environments, the cross-section of steel will gradually become thinner due to corrosion. If the initial thickness is close to the lower limit of the tolerance, the remaining thickness may exceed the critical value of the bearing capacity faster, shortening the service life of the structure.
Q:What impact does the thickness error of galvanized angle steel have on construction, installation and economy?
A:1. Component size matching
Assembly error: When multiple components are connected (such as steel truss nodes), inconsistent thickness tolerances may cause hole position offset and component length error accumulation, affecting installation accuracy, and even requiring on-site cutting or welding, increasing construction costs and construction period.
2. Material cost and waste
The impact of positive tolerance: The actual thickness exceeds the nominal value (such as + 0.5mm) will increase the amount and cost of steel (the price of steel per ton is about 4,000~6,000 yuan), but has no negative impact on the bearing capacity (it should be noted that the self-weight of the component increases the additional load on the foundation).
The risk of negative tolerance: If the thickness of the batch material is unqualified, it may lead to the return of the entire batch or reinforcement, causing construction delays and economic losses.