Читать книгу Properties for Design of Composite Structures - Neil McCartney - Страница 31

The situation simplifies when the material is linear thermoelastic and isotropic so that the stress-strain relations are

(2.157)

where E is Young’s modulus, ν is Poisson’s ratio, α is the thermal expansion coefficient and The inverse form is

(2.158)

When the stress field is hydrostatic so that σij=−pδij, and because σkk≡σ11+σ22+σ33, it follows from (2.157) that

(2.159)

The inverse form (2.158) may be written as

(2.160)

where λ and μ are Lamé’s constants, μ being the shear modulus, which can be calculated from Young’s modulus and Poisson’s ratio as follows:

(2.161)