A review on the mechanical properties of cement-based materials measured by nanoindentation

High-throughput solid solution strengthening characterization in high entropy alloys

Theoretical model for predicting uniaxial stress-strain relation by dual conical indentation based on equivalent energy principle

Fatigue damage evolution and lifetime prediction of welded joints with the consideration of residual stresses and porosity

Reverse analysis of constitutive properties of sintered silver particles from nanoindentations

Estimating constitutive equation of structural steel using indentation

This study describes a method that allows estimation of the equi-biaxial residual stress (σR), yield strength (σy), the strain hardening exponent (n), and the ratio (α) between strain at starting-point of strain hardening (est) and yield strain (ey) of structural steel from the load-depth curve of one sharp indentation test. In this method, the relationships between the structural steel properties, residual stress, and the characteristics of the indentation loading-unloading curves were established in the form of dimensionless functions via extensive finite element (FE) analyses. Based on the FE analysis results of the indentation process with a large number of different material properties combinations, the effects of residual stress and plastic parameters on the indentation response were investigated, and a reverse algorithm for estimating four unknown quantities (σR, σy, n, and α) of steel from an indentation test was proposed. A stress-applying apparatus that allows the introduction of a compressive or tensile stress to the sample by applying a compressive or tensile force and maintaining the stress after releasing the force was also developed in this study. Indentation and tensile tests of structural steels (SS400 and SM490) were carried out and the proposed algorithm was validated through both numerical analyses and experimental results.

Determination of equi-biaxial residual stress and plastic properties in structural steel using instrumented indentation

In this paper, a method for identification of the plastic properties of structural steels that exhibit a plastic plateau in their stress-strain curve from spherical indentation was proposed based on the results from extensive dimensional analyses and finite element (FE) simulations. Three explicit relationships, which related the properties of structural steel to the response from spherical indentation, were established. Considering that elastic modulus of structural steel was priori known since it can be extracted from the conventional methods, the plastic parameters of steel including yield strength ( σ y ), the strain hardening exponent ( n ), and the ratio ( α ) between the strain at beginning-point of strain hardening ( e st ) and the yield strain ( e y ) can be determined from a spherical indentation load-depth ( P-h ) curve using three proposed dimensionless functions. The spherical indentation process was simulated by using a finite element program, and a large number of analyses with different combinations of steel properties were conducted. From the FE analyses results, the functions were established from regression analyses, and a reverse algorithm was suggested. Spherical indentation, tensile tests, reverse analyses were carried out on three different structural steels (SS400, SM490, and SM520) to validate the proposed algorithm.

Identification of the plastic properties of structural steel using spherical indentation

Determination of mechanical properties in SM490 steel weld zone using nanoindentation and FE analysis

Estimation of microstructural compositions in the weld zone of structural steel using nanoindentation

Thai-Hoan Pham

Papers

Estimating constitutive equation of structural steel using indentation

Determination of equi-biaxial residual stress and plastic properties in structural steel using instrumented indentation

Identification of the plastic properties of structural steel using spherical indentation

Determination of mechanical properties in SM490 steel weld zone using nanoindentation and FE analysis

Estimation of microstructural compositions in the weld zone of structural steel using nanoindentation