Mathematical Problems in Engineering

Research Article

Spectral Classification of Non-Coaxiality for Two-Dimensional Incremental Stress-Strain Response

Table 1

Orientation angle and ratio of principal stress increments.
Stress increments matrix 𝜃 𝑑 𝜎 𝑅 𝑑 𝜎
𝑑 𝜎 1 0 0 𝑑 𝜎 2 0 𝑑 𝜎 1 𝑑 𝜎 2
𝑑 𝜎 2 0 0 𝑑 𝜎 1 𝜋 / 2 𝑑 𝜎 2 𝑑 𝜎 1
− 𝑑 𝜎 1 0 0 𝑑 𝜎 2 𝜋 / 2 − 𝑑 𝜎 1 𝑑 𝜎 2
𝑑 𝜎 1 0 0 − 𝑑 𝜎 2 0 − 𝑑 𝜎 1 𝑑 𝜎 2
− 𝑑 𝜎 1 0 0 − 𝑑 𝜎 2 𝜋 / 2 𝑑 𝜎 1 𝑑 𝜎 2