Theories of failure Shraddha Bharti

4.120 Principal stresses at a point are 80 N/mm2 and 40 N/mm2, both tensile. The yield stress in simple tension for this material is 200 N/mm2 The values of factors of safety according to maximum principal stress theory and maximum shear stress theory, respectively, are a) 2.5 and 2.5 2.5 and 5 (c) 5 and 5 (d) 5 and 1.67 LESE: 2016]

1 20 2 2- X 2-

4.119 A structural element is subjected to pure shear of 80 N/mm2, as shown in the figure. The yield stresses both in tension and in compression are 240 N/mm2. According to the maximum normal stress theory, the factors of safety in . tension and compression are, respectively, 80 N/mm2 80 N/mmi 80 N/mm 2 80 N/mm (a) 2 and 2 (c) 3 and 3 (b) 2.5 and 2.5 (d) 4 and 4 ESE: 2016]

go -80 30

4.115 A structural element is subjected to a two- dimensional stress system, wherein 1-225 N/mm2 (tensile) with 2 being compressive. The yield stress in both simple tension (g)t and simple compression (g)c ls 250 N/mm2 and u 0.25. What is the value of o2, according to Maximum Strain Theory? (a) 200 N/mm2 (b) 150 N/mm2 (c) 125N/mm2 (d) /100 N/mm2 [ESE: 20151

2 lIs. duna *o theo So-225-25-100 O.2.5 . 2S

4,114 Amachine element develops principal stresses of magnitudes 2Pand P. What is the maximum magnitude of Pbefore the material reaches the yield stress f, as per Distortion Shear Energy Theory? (a) f (b) L 2 (d 213 [ESE: 2015)]

2r 114 Acecrd m Sheau eneg thee 12 G , 12G S G 2. 2 2 V3

5 lessons,

41m 47s

Enroll

199

✕Download

Shraddha Bharti

B.tech civil 2017 WBUT || M.Tech environmental 2020 NIT Durgapur || GATE 2017 and 2018 || love teaching, traveling, learning

U

Unacademy user

Md safiqul alam

8 months ago

sir g 1st & 2nd method not a perfect.....

0

Reply

Gg

Gaurav gupta

a year ago

mam ,in 1 qns you solve only 1 value of max shear stress but if u slve 3 values of max shear stress and take max value of them the answer will different clear my doubt??

0

Reply

Shraddha Bharti

a year ago

No dear answer will be same.... Because you have to take the max of 3 shear stress..... Please try it yourself once

Gg

Gaurav gupta

a year ago

max shear stress is 40 if we calculate 3 valuue and then fos is 2.5

Shraddha Bharti

a year ago

Yes.... You are right.... If we consider the stresses in 3 dimension then the answer would be 2.5..... But since nothing is mentioned in the question then we are considering the stresses to be in the 2 dimensions only..... And for 2 D case the ans is 5

Gg

Gaurav gupta

a year ago

okk thanks