![Fig. 12 - SIF [MPa m ] vs. Maximum stretch [%].](/figures/fig-12-sif-mpa-m-vs-maximum-stretch-of1o602p.webp)
Q2. Why is HSLA steel widely used in different industries and systems?
Due to their better strength-to-weight ratio as compared to carbon steels, and despite their sensibility to SCC in certain environments such as moist air and water, HSLA steel is broadlyused in different industries and systems.
Q3. What is the peridynamic model used to model the mechanical behaviour of the material?
Microstructural data are used to model the mechanical behaviour of the material and a novel peridynamic hydrogen grain boundary diffusion model is introduced.
Q4. What is the simplest way to determine the response of a material to different loading conditions?
In order to determine the response of materials and structures subjected to different loading conditions, CCM was introduced and has been used to analyse numerous engineering problems.
Q5. What is the peridynamic force between material points x and x?
In the case of an elastic material, the peridynamic force, as a result of the interaction(bond) between material points x and x , can be expressed as:c s y y fy y (2)where y represents the location of the material point x in the deformed configuration, i.e., y x u .
Q6. What is the critical stretch parameter for peridynamic bonds?
In Eq. (5), i and j refer to a generic particle and its neighbour respectively, jV denotes thevolume of particle j , ij is the initial length of the bond between particles i and j , and Aqand Bq represent the number of peridynamic bonds along the directions associated with A and B , respectively.
Q7. What is the average micro-branching width predicted by the numerical model?
The average micro-branching width predicted by the numerical model is on the order of 60 μm.SIF = 40.3 MPa m (d), SIF = 48.55 MPa m (e).
Q8. What are the main limitations of the meshless method?
FEM cell mesh cohesive elements do not allow the analysis of arbitrary crack paths and often lead to mesh dependence and numerical convergence issues.
Q9. What is the method used for the discretization and solution of the problem?
For the discretization and solution of the problem, a commercial finite element software, ANSYS, is used by following the approach given in Macek and Silling (2007).
Q10. What is the peridynamic definition of failure?
As mentioned earlier, peridynamics, originally introduced for the prediction of mechanical deformations and material failure, has been extended to represent other fields including thermal (Madenci and Oterkus, 2014), electrical (Gerstle et al. 2008) and moisture (Oterkus et al. 2014) fields.
Q11. What can be done to improve the results of the present study?
the present study can serve as a starting point for more detailed SCC investigations: more complex geometries and loading conditions, 3D models and multiple cracks.
Q12. What is the governing equation for peridynamics?
The peridynamics’ governing equation can be written as: , , , , dV , H t t t t x xx u x f u x u x x x b x (1)where x , , tu x and , tu x denote the density, acceleration and displacement of thematerial point x at time t, respectively.
Q13. What is the critical energy release rate for a polycrystalline structure?
In case of linear elastic material and plane stress configuration, the critical energy release rate cG can be obtained from the fracture toughness,IcK , as follows (Anderson, 2005):EK G Icc2 (7)Similar to the approach adopted in (Rimoli and Ortiz, 2010), in this study, hydrogen grain boundary diffusion is described by considering type C kinetic regime (cf. (Harrison, 1961)) using the widely accepted Fisher model (Fisher, 1951).
Q14. How is the peridynamic model able to capture the width of micro-branching?
the present peridynamic model is also capable of capturing the width of micro-branching observed during the experiments (cf. Section 4.6), i.e., an average 40 μm of experimental microbranching width (Hirose and Mura, 1984).