Numerical simulation of energy effects in laser bending of thick steel plate

Author(s):  
Pei Jibin ◽  
Zhang Liwen ◽  
Wang Cunshan ◽  
Dong Chuang
2016 ◽  
Vol 85 (3) ◽  
pp. 282-286
Author(s):  
Motomichi YAMAMOTO ◽  
Kenji SHINOZAKI ◽  
Hiroshi YAJIMA ◽  
Tsutomu FUKUI ◽  
Shin NAKAYAMA ◽  
...  

Author(s):  
Kang-Yul Bae ◽  
Young-Soo Yang ◽  
Myung-Su Yi ◽  
Chang-Woo Park

To manufacture a steel structure, in the first step, raw steel plate needs to be cut into proper sizes. Oxy-fuel flame is widely used in the cutting process due to its flexibility with respect to accessibility, plate thickness, cost, and material handling. However, the deformation caused by the cutting process frequently becomes a severe problem for the next process in the production of steel product. To decrease the deformation, the thermo-elasto-plastic behavior of the steel plate in the cutting process should be analyzed in advance. In this study, heat sources in oxy-ethylene flame cutting of steel plate were modeled first, and the heat flow in the steel plate was then analyzed by the models of the heat sources using a numerical simulation based on the finite element method. To verify the analysis by the numerical simulation including the models, a series of experiments were performed, and the temperature histories at several points on the steel plate during the cutting process were measured. Moreover, the predicted sizes of the heat-affected zone by the numerical simulations according to the variation in the cutting parameters were compared to the experimental results. The power functions of the relationship between the sizes of the heat-affected zone and cutting parameters were obtained by the recursion analysis using the correlation between the results and parameters. The results of the numerical simulation showed good agreement with those of the experiments, indicating that the proposed models of the heat sources and thermal analysis were feasible to analyze the heat flow in the steel plate during the cutting process.


2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Théophile Vitoussia ◽  
Alain Brillard ◽  
Justin Bertsch ◽  
Olivier Allgaier ◽  
Gontrand Leyssens ◽  
...  

AbstractIn Sub-Saharan countries, cooking is usually done at a domestic scale using rudimentary stoves with wood or charcoal as combustibles. To improve the cooking behavior and reduce the deforestation, an improved pellet cookstove was conceptualized with guiding ideas in mind such as simplicity, robustness and ability to burn pellets built with local wood residues under a natural draught. Combustion and water ebullition tests were performed with two configurations of the upper part of the cookstove: thick steel plate or ring, and with standardized EN+ pellets as combustible. The main pollutant gases (CO, CO2 and NOx), together with O2, were continuously measured at different positions of the cookstove during a water ebullition test with the ring configuration. The levels measured above the pot were lower than the thresholds currently proposed by the World Health Organization. Simple and phenomenological thermal models were proposed to simulate the plate, or ring, and water temperatures during the combustion or water ebullition tests and to determine the intrinsic convection coefficients. The maximal relative differences between the experimental and simulated temperatures were computed between 7 and 21%. The stove power was evaluated at 4336 ± 23 W. The cookstove yield for the water ebullition test with the ring configuration was computed equal to 12.3 ± 0.1%, slightly lower than that of cookstoves previously analyzed in the literature.


Author(s):  
Huiyun Li ◽  
Guangyu Shi

The steel plate reinforced concrete (SC) walls and roofs are effective protective structures in nuclear power plants against aircraft attacks. The mechanical behavior of the concrete in SC panels is very complicated when SC panels are under the action of impacting loading. This paper presents a dynamic material model for concrete subjected to high-velocity impact, in which pressure hardening, strain rate effect, plastic damage, and tensile failure are taken into account. The loading surface of the concrete undergoing plastic deformation is defined based on the extended Drucker–Prager strength criterion and the Johnson–Cook material model. The associated plastic flow rule is utilized to evaluate plastic strains. Two damage parameters are introduced to characterize, respectively, the plastic damage and tensile failure of concrete. The proposed concrete model is implemented into the transient nonlinear dynamic analysis code ls-dyna. The reliability and accuracy of the present concrete material model are verified by the numerical simulations of standard compression and tension tests with different confining pressures and strain rates. The numerical simulation of the impact test of a 1/7.5-scale model of an aircraft penetrating into a half steel plate reinforced concrete (HSC) panel is carried out by using ls-dyna with the present concrete model. The resulting damage pattern of concrete slab and the predicted deformation of steel plate in the HSC panel are in good agreement with the experimental results. The numerical results illustrate that the proposed concrete model is capable of properly charactering the tensile damage and failure of concrete.


AIP Advances ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 095324
Author(s):  
Hongfu Qiang ◽  
Xinya Sun ◽  
Zhaojun Zhu ◽  
Huang Quanzhang ◽  
Shang Hehao

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