PSI - Issue 13

Shuai Wang et al. / Procedia Structural Integrity 13 (2018) 1940–1946 Author name / Structural Integrity Procedia 00 (2018) 000 – 000

1942

3

Fig.2. The tensile testing of plate tensile specimen

3. Finite element model 3.1. Material mode The linear elastoplastic hardening model can approximately express the behavior of the stress-strain curve after the material yields. Linear elastic plastic hardening model as show in Fig.3 [15] .



 E

 

E



O

Fig.3. Linear elastic plastic hardening model

The basic equation for the linear elastoplastic hardening model is

(1 )        = − + E   = E

( (

) )

0      

(1)



0

0

where ε and σ are strain and stress, respectively, E is Young's modulus, δ is the reduction factor of the material, σ 0 is the yield strength of the material. The true stress-strain curve of cold worked 316L stainless steel can generally be expressed in linear elastoplastic hardening model. The material mechanical properties of austenitic 316L stainless steel as shown in Table 2. To obtain the mechanical properties of 316L stainless steel under different cold working amounts, the simulation calculation results were controlled by adjusting the yield limit σ 0 and the reduction factor δ, and compared with the stress-strain curve obtained from uniaxial tensile experiment. In the numerical simulation process, the input yield limit σ 0 , reduction factor δ and other parameters are the mechanical performance paramete rs under different cold working conditions.

Table 2. Material mechanical properties.

ν

Material

E/GPa

σ 0 /MPa

δ

316L

190

0.3

Predetermined Predetermined

3.2. Geometric model A geometric model is drawn based on the geometric size of a plate-shaped specimen. To ensure that the loading conditions of numerical simulation are consistent with the physical experiments, fixing holes and loading holes are