﻿ Data description/conditions

Data description/conditions

Specification of stress-strain relation of pipe material (Input Table)

Data description/conditions:

MATREF:

Reference name of material data

Unique name in list

Rm:

Ultimate tensile strength

> 0. / Undefined

SIGEPS:

Type of stress-strain relation (diagram)

Undefined / Prescribed names: Bilinear, Ductile, DS-Hardening, Cyclic

(If Undefined, the Bilinear diagram is applied in case of material non linear calculations.
Bilinear = Bilinear stress-strain relation
Ductile = Ductile stress-strain relation
DS-Hardening = Ductile stress-strain relation with Strain Hardening
See below for further description.)

K-VALUE:

(cyclic) hardening coefficient

> 0. if SIGEPS = CYCLIC / Undefined

N-VALUE:

(cyclic) hardening exponent

> 0. if SIGEPS = CYCLIC / Undefined

CHKEPS:

Check strain of pipe material

> 0. / Undefined

(If UNDEFINED, the value is set to 7 or 5 permil (see NEN 3650). This strain is considered to be an allowable strain in case of material non-linear analysis. If exceeded, a warning is given.)

The diagram for the stress-strain relation can be described approximately by an analytical function, for cyclic loading by the equation:

e = s/E + (s/K)**(1/N)

where:        e = strain
s = stress
E = Young's modulus
K = hardening coefficient
N = hardening exponent

Built-in stress-strain relations:

 BILIN Stress-Strain diagram DUC Stress-Strain diagram DSH Stress-Strain diagram Strain / Yield-strain Stress / Yield-stress Strain / Yield-strain Stress / Yield-stress Strain / Yield-strain Stress / Yield-stress 0.000 0.000 0.000 0.000 0.667 0.667 1.000 1.000 0.450 0.450 0.926 0.800 ~ 1.000 0.650 0.600 1.111 0.850 0.830 0.700 1.370 0.900 1.080 0.800 1.667 0.940 1.300 0.850 1.889 0.960 1.700 0.900 2.000 0.970 2.300 0.950 2.259 0.980 2.830 0.980 2.630 0.990 3.400 1.000 3.370 1.000 ~ 1.000 9.000 1.001 18.000 1.167 27.000 1.267 36.000 1.325 45.000 1.358 54.000 1.375 63.000 1.390 ~ 1.390

The above diagram shows the various built in (dimensionless) stress-strain relations (yield-strain = Re/Emod). The following diagram shows various stress-strain relations for a specific situation:

H310181, last changed: 14/09/2016

Table description

Table error description