Solve Problem 15.21 if the action line of load P is at the center of the tip of the crack....

Solve Problem 15.21 if the action line of load P is at the center of the tip of the crack.

Problem 15.21

A bar of titanium alloy (Ti-6A1-4Sn-lV) has a rectangular cross section (t = 30 mm and 2c = 300 mm), has a length L = 1 m, and is heat-treated to give the material properties in Table 15.1. The bar is subjected to an axial load P whose action line is at the centerline of one of the 30-mm edges. If a transverse edge crack at the center of length L has the minimum length required for a plane strain state of stress, determine the magnitude of P to cause brittle fracture.

Table 15.1:

TABLE 15.1 KIC Critical Stress Intensity Factor (Fracture Toughness)a

aRoom temperature data.