Non-contact residual stress analysis method with displacement measurements in the nanometric range by laser made material removal and SLM based beam conditioning on ceramic coatings

Martínez-García, V.; Pedrini, Giancarlo; Weidmann, P.; Killinger, Andreas; Gadow, R.; Schmauder, Siegfried

doi:10.1016/j.surfcoat.2018.12.123

Cited by 8 publications

(4 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Due to the large temperature gradients and high-frequency heating-cooling cycles during the manufacturing process, it is difficult to monitor the temperature and thermal stress in real time during experiments. For the residual stress measurement, the experimental approaches, such as the neutron diffraction [16,17], X-ray diffraction [18], contour method [19] and semi-destructive hole drilling method [20,21], are costly and sometimes limited to surface measurements. Numerical simulations are efficient to study the mechanical behaviours during the manufacturing process [22].…”

Section: Introductionmentioning

confidence: 99%

Crystal plasticity model of residual stress in additive manufacturing using the element elimination and reactivation method

Grilli

Yushu

et al. 2021

Comput Mech

View full text Add to dashboard Cite

Selective laser melting is receiving increasing interest as an additive manufacturing technique. Residual stresses induced by the large temperature gradients and inhomogeneous cooling process can favour the generation of cracks. In this work, a crystal plasticity finite element model is developed to simulate the formation of residual stresses and to understand the correlation between plastic deformation, grain orientation and residual stresses in the additive manufacturing process. The temperature profile and grain structure from thermal-fluid flow and grain growth simulations are implemented into the crystal plasticity model. An element elimination and reactivation method is proposed to model the melting and solidification and to reinitialize state variables, such as the plastic deformation, in the reactivated elements. The accuracy of this method is judged against previous method based on the stiffness degradation of liquid regions by comparing the plastic deformation as a function of time induced by thermal stresses. The method is used to investigate residual stresses parallel and perpendicular to the laser scan direction, and the correlation with the maximum Schmid factor of the grains along those directions. The magnitude of the residual stress can be predicted as a function of the depth, grain orientation and position with respect to the molten pool. The simulation results are directly comparable to X-ray diffraction experiments and stress–strain curves.

show abstract

Section: Introductionmentioning

confidence: 99%

Crystal plasticity model of residual stress in additive manufacturing using the element elimination and reactivation method

Grilli

Yushu

et al. 2021

Comput Mech

View full text Add to dashboard Cite

show abstract

“…Due to the large temperature gradients and high-frequency heating/cooling cycles during the manufacturing process, it is difficult to monitor the temperature and thermal stress in real time during experiments. For the residual stress measurement, the experimental approaches, such as the neutron diffraction [11], X-ray diffraction [12], contour method [13] and semi-destructive hole drilling method [14,15], are costly and sometimes limited to surface measurements. Numerical simulations are efficient to study the mechanical behaviour during the manufacturing process.…”

Section: Introductionmentioning

confidence: 99%

Crystal plasticity model of residual stress in additive manufacturing

Grilli,

Hu,

Yushu

et al. 2021

Preprint

View full text Add to dashboard Cite

Selective laser melting is receiving increasing interest as an additive manufacturing technique. Residual stresses induced by the large temperature gradients and inhomogeneous cooling process can favour the generation of cracks. In this work, a crystal plasticity finite element model is developed to simulate the formation of residual stresses and to understand the correlation between plastic deformation, grain orientation and residual stresses in the additive manufacturing process. The temperature profile and grain structure from the thermal-fluid flow and grain growth simulations are implemented into the crystal plasticity model. An element elimination and reactivation method is proposed to model the melting and solidification and to reinitialise state variables, such as the plastic deformation, in the reactivated elements; it represents a step forward compared with previous methods based on the stiffness degradation of liquid regions. The method is used to investigate residual stresses parallel and perpendicular to the laser scan direction, and the correlation with the maximum Schmid factor of the grains along those directions. The magnitude of the residual stress can be predicted as a function of the depth, grain orientation and position with respect to the molten pool.

show abstract

“…Optical interferometric techniques are widely used for residual stress analyses in conjunction with semi-destructive techniques such as the sectioning, hole drilling, and contour methods. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. In these methods, the material around a residually stressed area is removed step by step.…”

Section: Introductionmentioning

confidence: 99%

“…At each step, the displacement resulting from the last material removal is measured with the optical interferometry. Some authors use digital holography [7][8][9] and other use ESPI [10][11][12][13][14][15][16][17][18] for the optical technique. Recent studies report non-contact methods to relieve the residual stress using laser ablation [9] or laser annealing [18].…”

Section: Introductionmentioning

confidence: 99%

Effect of Residual Stress on Thermal Deformation Behavior

et al. 2019

View full text Add to dashboard Cite

This paper discusses a non-destructive measurement technique of residual stress through optical visualization. The least amount of deformation possible is applied to steel plates by heating the specimens +10 °C from room temperature for initial calibration, and the thermal expansion behavior is visualized with an electronic speckle pattern interferometer sensitive to two dimensional in-plane displacement. Displacement distribution with the thermal deformation and coefficient of thermal expansion are obtained through interferometric fringe analysis. The results suggest the change in the thermal deformation behavior is affected by the external stress initially applied to the steel specimen. Additionally, dissimilar joints of steel and cemented carbide plates are prepared by butt-brazing. The residual stress is estimated based on the stress dependence of thermal expansion coefficient.

show abstract

Non-contact residual stress analysis method with displacement measurements in the nanometric range by laser made material removal and SLM based beam conditioning on ceramic coatings

Cited by 8 publications

References 16 publications

Crystal plasticity model of residual stress in additive manufacturing using the element elimination and reactivation method

Crystal plasticity model of residual stress in additive manufacturing using the element elimination and reactivation method

Crystal plasticity model of residual stress in additive manufacturing

Effect of Residual Stress on Thermal Deformation Behavior

Contact Info

Product

Resources

About