Question

QUESTION2 What is common between the plasticity mechanism of semi-cystalline plassic polymers and polycnystalline metalbs? O slips justify both O untangling the amorphous regions justifies polymeric plasticity while slips justity metallic olasticity 0.5 points Save Answer chain orientation justifies polymeric plasticity while the dislocation theory justifies metalic plasticity chanege inthe equaterium distance jesifits both 1 points Save Answer QUESTION 3 Estimate the upper l mit of the eastK modulus of concrete (45 decimal points Elastic modulus of gravel 150 MPa Elastic modulus of clean sand- 55 MPa Elastic modulus of cement- 13 GPa grave, 33% sand and 22% cement, using the following information wre" your answer in MPa with 4 Tip: Extend and use the rule of mixture to three components. 0.5 pointsSave Save and Submit Save All Answers to save ond suome MacBook Air

Answer 1

Q2- second option is correct

Q3-

The problen can be solved from strain compatibility

Let total cross sectional area be A

Area of gravel=0.45A

Area of sand=0.33A

Area of cement=0.22A

Let total deformation be d and initial length be L

Strain of all materials is equal and equal to k

Stress in gravel=k*Eg

Stress in sand=k*Es

Stress in cement=k*Ec

Let equivalent Modulus of elasticity be E

k*E*A=k*Eg*0.45A+k*Es*0.33A+k*Ec*0.22A

E=0.45*150+0.33*55+0.22*13000=2945 MPa

This is the required answer