Picosecond-Resolved Raman Response of a Si Nanotip for Probing Temperature and Thermal Stress in the Confined Regime under Laser Heating

Laser-assisted laser peen forming (LALPF) is proposed as a hybrid process to combine laser heating and laser peening to improve the bending capability of laser peen forming (LPF) effectively. To predict LALPF-induced bending deformation and mechanism of bending capability improvement, a sequentially coupled modeling approach is established by integrating three models, i.e., a thermoelastic-plastic model to predict the temperature, a dynamic model to obtain the eigenstrain of laser shock, and an eigenstrain model to predict the bending deformation. The effects of temperature, thermal stress, and thermal plastic strain of laser heating and the coupling effects on the bending deformation were investigated. The results show that the interaction of temperature and thermal stress are the dominant factors contributing to the improvement of bending capability.

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Thermal Stress-Focusing Effect Following Pulse-Laser Heating of a Sphere

The proceedings of the JSME annual meeting ◽

10.1299/jsmemecjo.2004.1.0_31 ◽

2004 ◽

Vol 2004.1 (0) ◽

pp. 31-32

Author(s):

Toshiaki HATA

Keyword(s):

Thermal Stress ◽

Pulse Laser ◽

Laser Heating ◽

Focusing Effect ◽

Pulse Laser Heating

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Thermal Stress Associated With Non-Fourier Heat Conduction in Femtosecond Laser Heating of Multilayer Metallic Films

Volume 8B: Heat Transfer and Thermal Engineering ◽

10.1115/imece2018-86144 ◽

2018 ◽

Author(s):

Swarup Bag ◽

M. Ruhul Amin

Keyword(s):

Thin Film ◽

Heat Conduction ◽

Thermal Stress ◽

Temperature Distribution ◽

Pulse Laser ◽

Laser Heating ◽

Laser Source ◽

Phase Lag ◽

Dual Phase ◽

Fourier Heat Conduction

In the present work, the deformation behavior in metallic film subjected to ultra-short laser heating is investigated. Static thermo-elastic behavior is predicted for 100 nm thin film of either single layer or multiple layers. The temperature distribution is estimated from dual-phase lag non-Fourier heat conduction model. The maximum temperature after single pulse is achieved 730 K. The temperature profile for this pulse laser is used to compute elastic stress and distortion field following the minimization of potential energy of the system. In the present work, the simulation has been proposed by developing 3D finite element based coupled thermo-elastic model using dual phase lag effect. The experimental basis of transient temperature distribution in ultra-short pulse laser is extremely difficult or nearly impossible, the model results have been validated with literature reported thermal results. Since the temperature distribution due to pulse laser source varies with time, the stress analysis is performed in incremental mode. Hence, a sequentially coupled thermo-mechanical model is developed that is synchronized between thermal and mechanical analysis in each time steps of transient problem. The maximum equivalent stress is achieved 0.3 GPa. Numerical results show that the predicted thermal stress may exceeds the tensile strength of the material and may lead to crack or damage the thin film.

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