AE-CIVE 265 - Lecture 1A - Elastic Material Properties - 2024 PDF

Lecture 1 – Part A – Key Messages The elastic stress-strain behaviour of materials can be described in a number of ways. This behaviour can be measured using simple axial tension and compression tests. Material elastic stiffness can be explained by the stretching of atomic bonds....

Lecture 1 – Part A – Key Messages The elastic stress-strain behaviour of materials can be described in a number of ways. This behaviour can be measured using simple axial tension and compression tests. Material elastic stiffness can be explained by the stretching of atomic bonds. 1  Mechanical Properties (σ) F Material properties A0 Range of stress is in change stress MPa axial load 2 (ε) ε = 0.01 or 1% li Range of stress is in l0 Micro-strain 3 Metal Tension Test [ASTM E8M] 350 300 250 6061-T6 Stress (MPa) 200 Aluminum 150 100 50 0 0.00 0.05 0.10 0.15 Strain 4  Concrete Compression Test Common cylinder sizes (D x L): [Prof. West] → 150 x 300 mm → 100 x 200 mm → L/D = 2.0 D L 5  (τ) – units Pa, MPa F A0 F shear load 6 (γ) F w θ l0 F 7 [Callister and Rethwisch] 8 9 bonds stretch but don’t break 10 11 (E) 12 “hardening” “softening” 13  Overestimating Underestimating (safe side) Linearizing the behavior makes calculation easy. [Mamlouk and Zaniewski] 14  z x y εz = Δlz / l0z εx = Δlx / l0x εy = Δly / l0y 15 [Callister and Rethwisch] 16 [Callister and Rethwisch] 17 “Auxetic Foams” www.youtube.com/watch?v=PLDbSWSm5i8 18 (G) same in every direction 19 20