P5.20 A 2.75 kN force acts on the vertical plate, which in turn is connected to the horizontal truss by five 5 mm diameter rivets (Figure P5.20). (a) If the rivets share the load equally, determine the shear stress in them. (b) In a worst-case scenario, four of the rivets have corroded, and the load is carried by only one rivet. What is the shear stress in this case? 2.75 kN Rivet detail

P4.9 The pin-connected structure is subjected to a load P P as shown in Figure P4.9. Inclined member (1) has a cross-sectional area of 250 mm² and has a yield strength of 255 MPa. It is connected to rigid member ABC with a 16-mm-diameter pin in a double shear connection at B. The ultimate shear strength of the pin material is 300 MPa. For inclined member (1), the minimum factor of safety with respect to the yield strength is FSmin = 1.5. For the pin connections, the minimum factor of safety with respect to the ultimate strength is FSmin = 3.0. (a) Based on the capacity of member (1) and pin B, determine the maximum allowable load P that may be applied to the structure. (b) Rigid member ABC is supported by a double shear pin connection at A. Using FSmin= 3.0, determine the minimum pin diameter that may be used at support A. 1.8 m 1.4 m C B 2.3 m (1) FIGURE P4.9 D

(5) A gas engine valve spring is loaded to 35kgf when the valve is closed & 52kgf hen the valve is open. The valve lift is 8mm. The outside diameter is to be from 38mm~45mm, & the permissible stress is 413N/mm2 . Determine: (a) the wire & outside diameter; (b) the number of effective coils; (c) the free length when it is squared & ground.

20 (B) An air vessel, which is made of steel in 2 m long. It has an external diameter 44 cm and is 2 cm thick. 1. Calculate the permissible pressure difference allowed between the inside and outside if the longitudinal stress in the wall must not exceed 20 MPa. 2. Determine longitudinal and hoop strains. 3. Calculate the change in diameter and change in volume. Take E = 200 GPa and v = 0.3