Question 3.9: A wall hook has a base size of 30 × 30 × 5 mm. The hook as a...
A wall hook has a base size of 30 × 30 × 5 mm. The hook as a diameter of Φ5 mm, and its center is offset from the top surface of base by 7.5 mm. The wall hook is printed with ABS plastics, and the yield strength is given as S_{y} = 35 MPa. Assume the safety factor is n_{d} = 2.0, determine the maximum load the hook can carry without a failure.
Using the SolidWorks Simulation, the wall hook is modeled as shown in Fig. 3.41a. The corresponding FEA model is defined in Fig. 3.41b; it is assumed that the hook is fixed on wall (e.g., the base plate), and the nominal force F_{\text{nominal}} = 10 N is applied on hook. The simulation of the FEA model results in the stress and displacement distribution, which are shown in Fig. 3.42a, b, respectively.
The maximum von Mises stress \sigma _{max} is 6.585 MPa subjected to a nominal force F_{\text{nominal}} = 10 N. Since the FEA model is a linear model, the stress is proportional to the load, and the maximum allowable load for a safety factor of n_{d} = 2.0 can be determined as
F_{\text{allowable}}=\frac{F_{\text{nominal}} }{n_{d} }\frac{S_{y} }{\sigma _{max} } =\left(\frac{10}{2} \right) \left(\frac{3510^{6} }{6.58510^{6} } \right) = 26.58(N)
