Conoscenza di base
Code-check of bolts and preloaded bolts according to Hong Kong Code
Preloaded bolts are checked for shear slip capacity and combination of tension and shear.
Shear capacity
Shear capacity of preloaded bolts is determined according to Cl. 9.3.6.2 as:
\[ P_{SL} = 0.9 \cdot K_s \cdot \mu \cdot P_0 \]
where:
- \(K_s\) – hole coefficient taken as
- for standard holes \(K_s = 1.0\)
- for oversized holes \(K_s = 0.85\)
- for slotted holes \(K_s = 0.7\)
- \(\mu\) – slip factor between connected parts from Table 9.7; editable in Code setup
- \(P_0\) – minimum proof loads of bolts specified in relevant international or local standards
Combined tension and shear
Combined tension and shear is checked according to Cl. 9.3.8.2 as:
\[ \frac{F_s}{P_{SL}}+\frac{F_{tot}}{0.9\cdot P_0} \le 1.0 \]
where:
- \(F_s\) – shear force in a bolt
- \(P_{SL}\) – slip resistance of a preloaded bolt
- \(F_{tot}\) – total applied tension in the bolt including the prying force
- \(P_0\) – specified minimum proof load of a preloaded bolt