The hinged hole is coupled to the polished rod portion of the bolt and the coupled member in the form of a force in which the bolt rod is sheared at the joint surface of the coupled member; the bolt rod surface and the hole wall are squeezed. Therefore, the calculation should be based on the extrusion strength and shear strength, respectively. The shear calculation under alternating load is to set the bolt to bear the alternating working load, and the failure form is shearing. The design criterion is that the probability that the shear stress of the bolt is less than the shear fatigue strength must be greater than or equal to the reliability R(t) required by the design, expressed as: P(f-1>f)=P(f-1-f>0 ≥R(t), where f-1 is the shear fatigue strength of the bolt material, MPa; f is the shear stress of a single bolt, MPa. Select the bolt material and determine the strength distribution: first select the bolt material, the bolt performance level, the strength distribution is normal distribution, find the tensile strength eb, the yield limit eS. From the empirical formula: e-1=0.23(eb+eS) ;f-1=0.577e-1;ef-1=0.08f-1. Determine the bolt shear stress distribution: (1) The average working load of a single bolt is F: F = F / n, where F is the total lateral working load of the bolt group, N; n is the number of bolts. (2) The average cross-sectional area of ​​the bolt is A: πd2/4, where d is the diameter of the shear surface of the bolt, and the standard deviation of the area A is eA=πded/2. According to the manufacturing tolerance of the bolt diameter, find out The relationship between d and ed is: ed=0.001~0.002d. (3) The mean shear stress of the bolt is: f = FmA = 4Fmπd2, where m is the number of joint faces. The standard deviation of shear stress is: ef=4mπe2Fd4+4F2e2dd61/2. Solve the bolt diameter d according to the coupling equation: the coupling equation: Z=-f-1-fe2f-1+e2f. According to the required reliability R(t) value, the standard normal distribution table is checked, and the Z value of the coupling coefficient is obtained. Substituting the relevant parameters Z, f-1, f, ef-1, ef into the coupling equation, the bolt diameter d can be obtained, the thread standard can be checked, and the nominal diameter of the bolt can be determined. Floor Drains,Toilet Floor Drains,Bathroom Floor Drain,Shower Floor Drain With Cover kaiping aida sanitary ware technology co.,ltd , https://www.kpaidafaucets-jm.com