A carpenter glues a pair of cylindrical wooden logs by bonding their end faces at an angle of q = 30° as shown in the figure

Q. A carpenter glues a pair of cylindrical wooden logs by bonding their end faces at an angle of q = 30^° as shown in the figure.

The glue used at the interface fails if

Criterion 1: the maximum normal stress exceeds 2.5 MPa. Criterion 2: the maximum shear stress exceeds 1.5 MPa.

Assume that the interface fails before the logs fail. When a uniform tensile stress of 4 MPa is applied, the interface

A. fails only because of criterion 1

B. fails only because of criterion 2

C. fails because of both criteria 1 and 2

D. does not fail

Ans: fails because of both criteria 1 and 2