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NM2D3

\(N\)-\(M\) Interaction Inelastic Section (Nonlinear Hardening)

Reference

  1. 10.1061/JSENDH.STENG-12176

Syntax

Text Only
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section NM2D3 (1) (2...12) [(13) (14) (15) ...]
# (1) int, unique section tag
# (2) double, EA
# (3) double, EI
# (4) double, yielding axial force
# (5) double, yielding strong axis moment
# (6) double, d
# (7) double, isotropic hardening modulus, H
# (8) double, isotropic hardening saturation, s
# (9) double, isotropic hardening decay, m
# (10) double, kinematic hardening modulus, K_b
# (11) double, kinematic hardening base, K_a
# (12) double, linear density
# (13) double, a_i
# (14) double, b_i
# (15) double, c_i

In the above command, parameters (13), (14) and (15) form a triplet and can be appended as many groups as analyst wishes. The surface is assumed to possess the following form,

\[ f=\sum_{i=1}^na_ip^{b_i}m_s^{c_i}-d. \]

For example, the surface \(f=1.15p^2+m_s^2+3.67p^2m_s^2-c\) can be expressed as follows.

Text Only
1
section NM2D3 (1) (2...12) 1.15 2. 0. 1. 0. 2. 3.67 2. 2.

The only validation implemented is the number of triplets. The command takes \(3n\) parameters and interprets them accordingly. Please make sure the definition is correct.