[Retracted] Image-Based Precision Measurement Technology for the Quality Inspection of Crane Boom Materials

Table 1

Common crane boom materials.

Metallic material	Safety factor	Allowable compressive bending stress	Allowable shear stress	Allowable end face to withstand stress
Q235	1.48	153.2	82.4	242.3
Q345	1.48	174.4	102.5	265.1
20	1.48	116.5	76.8	199.7
45	1.48	188.3	134.6	294.8
40Cr	1.48	268.7	159.9	368.5
20Cr	1.48	330.2	178.7	386.4