o Fr 3d 剪切强度(对于铆钉) 2F2×23.5×10 [ 51.8MPa < I mm3.14×172 4剪切强度（对于铆钉） A Fs  = 4 2 2 P d F  = 2 2 P d F  = 2 3 3.14 17 2 23.5 10    = = 51.8MPa   