Calculate the stress at the bottom of mid span in a prestressed concrete beam of size 350 × 500 mm is provided with a straight cable of 20 wires of 5 mm of bars stressed at 1500 N/mm2 at eccentricity 100 mm. Beam is subjected to UDL of 30 KN/m over a span of 8 m.
1
+6.22 N/mm2
2
- 9.05 N/mm2
3
+12.64 N/mm2
4
-6.22 N/mm2