Question

Problem 2 (30 points): Consider a rectangular composite lamina with θ-45° and the folloving orthotropic material properties: E.-140 GPa E2 10 GPa, G12-7 GPa, and v12-03. TheTamina is subjected to σ.-10 MPa, σ.-0 MPa, and ty a) Draw a correct and complete FBD of this lamina, including fiber angle and coordinate systems (5 pts ). If the value of τ is zero, sketch what the deformed lamina (with fibers) will look like and state what unusual composite behavior is being exhibited. (5 pts) b) c) Calculate the reduced stiffiness and transformed reduced stiffiess matrices for this lamina. (10 pts) d) Calculate the value of τ that wil I keep the deformed shape a rectangle. Hint: think about which strain component must be zero for a shape to remain rectangular. (10 pts)

Answer 1

43 Solotion 2 FBD: e-45 (given) ng nelahon m" n2 2,η n | //. 재 Now we can caleulate Eru, and 1n eta= 4.883 X10-4 94 can easilg be 마he-wed thar staan in longitudinaldaechen

, duto, med comporte ban (c) Compltance matix: Hen오uc4,taene terma ee comp hence mafixto caludbe. dalchon shown above a」 m«MX multi lication, we cul caleulete cach team. aex 더 o, hene use g the sollowin faam し01-19

S11 S22 2 11 s2乙 3,2 Uing sbove equahmd, and puting thege values in the 93 We qu, 140-9 3. 019 13.012 10.0647 7(C) (d) Frem matrix Julafion (a), tㅏ can be early seen traf the diztoasion vectangulor phape composite happens because 4 사ear, 8taart element no 1-2. plregivert 12. 12 and last tem 4 matrix m = 6 (fan G-45") as wele.go we can do nothing to τ to Jugantne