Question

h based carbon fiber containing a known amount of single walled 5. Consider a pitc Sartbon nanotubes (SWNT), By adding small amounts of single walled carbon nanotubes SWNT) to the pitch prior to fiber pulling, the elastic fibers can be i the following questions a. (10 points) Estimate the elastic modulus for both the 1% and 5% SWNT loaded carbon fibers. modulus of the pitch based carbon ncreased. Use the figure below and the other information (given) to answer 700 swNT huling 200 0.903 9012 drain (om m (20 points) If we were to use the 5% SWNT loaded carbon fibers from, above to create a unidirectional fiber-reinforced composite with an epoxy polymer that had an elastic modulus of 3000 MPa, what would the longitudinal and transverse modulus of the composite be if the volume fraction of the fiber was 60%? Hint: Potentially useful equations: b. v, v E.-e,r, .E.는슷.는 4cn.r,,, .VJ. 6. (20 points) The plane strain fracture toughness of an aluninum alloy is 7.6 MPavm It has been determined that fracture results at a stress of 140 x 10 MPa when the critical internal crack length is 2 nm. For this same component and alloy, compute the maximum stress to which this material could be loaded without fracture when the internal crack length is 0.5 mm. (Hint Ku-rơVia, the crack length-2a).

Answer 1

stus 6so A Pa = 44.4S x103 MR 6,013S stain (mmmm-I) → gso 0.0125-O = 72x103 MR stnai SV. SIW NT ナ 는 Ef yf +PnYnー子1x.so + 3x.YO

Trans wise modulo cemposite. Et En Ct 0.4o 0.60 3 et