Chapter 13, Problem 7RQ

Q.2 The required design span for the beam given in Q.1 is increased to 18 ft. The design loads are the same as given in Q.1 Check the adequacy of a 10"x16" 10 Caribbean Pitch Pine – (Select Structural) for this these design conditions.

The timber floor framing for a building comprise floor joists using 2" wide nominal lumber is to be constructed as shown in Fig. 1. The Dead load (D) = 26 lbs./ft² (inclusive of joists and flooring) and the live load L= 40 lbs./ft². Lateral torsional buckling is prevented for all members and normal service conditions and temperatures are expected. (i) Design the floor joists using 2" wide nominal lumber using Southern Pine No. 1 (ii) Design the floor beams using Caribbean Pitch Pine (Select Structural). (Assume a 8" x 14” trial section to estimate beam self-weight for your initial design). Density of Caribbean Pitch Pine = 50 lbs/ft³ (800 kN/m³).

P12.38 WP At a point on the free surface of a stressed body, a normal stress of 64 MPa (C) and an unknown positive shear stress exist on a horizontal plane. One principal stress at the point is 8 MPa (C). The absolute maximum shear stress at the point has a magnitude of 95 MPa. Determine the unknown stresses on the horizontal and vertical planes and the unknown principal stress at the point.