Answer Happy

Q2 (2x2 points) A snap-on bottle top must carry on a considerably large amount of deflection without fracture. (1) Create a fracture toughness-modulus (K1c vs. E) bubble chart (Level 2) to identify appropriate polymers for such a snap-on bottle top that have a fracture toughness Kic greater than 1 MPa.m12 and a material index Kıc/E greater than 3x10-3 m112. Make a list of material(s) ranked by Kıc/E with brief comments. (2) If the critical deflection, 8, is defined as 3% of the bottle diameter, D, calculate the maximum crack length, a, which can be allowed on the surface of the bottle top for the candidate(s) identified in (1). Hint: 음 Kic where ε is the elastic strain πα E where ε is the elastic strain and it is given as change in diameter divided by diameter as 10.03x D D Please make sure to pay attention to the units, E is given in GPa in default mode of CES.