A wood specimen having a square cross section of 50 mm * 50 mm (actual dimensions) was tested in bending by applying a load at the middle of the span, where the span between the simple supports was...

A wood specimen having a square cross section of 50 mm * 50 mm (actual

dimensions) was tested in bending by applying a load at the middle of the

span, where the span between the simple supports was 700 mm The deflection

under the load was measured at different load levels as shown in Table P10.23.

a. Using a computer spreadsheet program plot the load–deflection

relationship.

b. Plot the proportional limit on the graph.

c. Calculate the modulus of rupture (flexure strength).

d. Does the modulus of rupture computed in (c) truly represent the extreme

fiber stresses in the specimen? Comment on the assumptions used to

compute the modulus of rupture and the actual response of the wood

specimen.