Numerical Simulation of Transient Temperature Field and Thermal Stress in the Electromagnetic Railgun

Author(s):  
JUN WANG ◽  
SHIYU WANG ◽  
BAOMING LI
2021 ◽  
Vol 233 ◽  
pp. 04046
Author(s):  
Changhao Zhang ◽  
Hu Li ◽  
Jianyu Yang ◽  
Huawei Lu ◽  
Peng Su

According to the structural characteristics of thin-walled parts, a model slicing method is proposed, and its mathematical process is established. The three-dimensional transient temperature field in the process of synchronous powder feeding laser cladding is studied and verified by numerical simulation method, and the thin-walled parts formed by later experimental processing are processed by the results of numerical simulation. Using the simulation results of temperature field as the basis for optimizing the processing parameters, the forming path of thin-walled parts is programmed and optimized, and the experimental verification shows the reliability of this method.


Author(s):  
Zhibing Lu ◽  
Xuedong Chen ◽  
Zhichao Fan ◽  
Jie Dong ◽  
Jinhua Zhu

Coke drum is typical industrial equipment which experiences complex thermal and mechanical cyclic load during its operation, and the thermal stress which is produced by the drastic change of temperature is the main cause of the cracking failure of coke drum. This paper aims at coke drum with 1.25Cr–0.5Mo steel, and is based on iterative algorithm. Then we simulate the process of liquid medium climbing the inner surface of coke drum in the stages of oil filling and water quenching with dynamic thermal boundary, and carry out the numerical calculation of transient temperature field of coke drum in main process stages for one operating cycle. After the comparison of simulated temperature values with the measured temperature data at several locations on the outer surface of coke drum, the appropriate equivalent coefficients of convective heat transfer will be obtained. The variation rules of transient temperature field for the key parts of coke drum are discussed. Based on the simulation results of temperature field, the thermal-structure coupling analysis of coke drum is carried out, and the variation characteristics of thermal stress on coke drum are studied later.


2012 ◽  
Vol 557-559 ◽  
pp. 2274-2278
Author(s):  
Ge Wang Shuai ◽  
Ping Fang ◽  
Zheng Hua Guo

In this paper, with the ANSYS, a 2D axisymmetric coupled thermo-electro-mechanical model was developed to analyze the spot welding process(RSW) of zinc coated steels with copper strips as an insert material between electrode and workpiece. A transient temperature field obtained from a prior performed thermal–electrical simulation of RSW process is applied as nodal load on the model to simulate the stress distribution. The temperature and stress distributions in such a welding process were obtained and compared with a conventional resistance spot welding process. The results show that using the same welding process parameters, the maximum transient temperature at the electrode surface is lower than the conventional RSW process due to the use of copper strips, which helps to extend electrode lifetime. In addition, the presence of inserted copper strip increased the resistance of welding system, thus generated much more heat to form larger nugget.


2014 ◽  
Vol 898 ◽  
pp. 233-236
Author(s):  
Jin Hong Ma ◽  
Xiao Han Yao ◽  
Bin Tao ◽  
Shuo Li

Controlled cooling of H-beam after rolling, can change the microstructure consituent,improve the strength and improve the general mechanical property and service performance. According to actual product, the rational thermal boundary condition adopted, three dimensional FEM model is established. Spray cooling is used. Transient temperature field and stress field is simulated by the FEM software ANSYS/Multiphysics when H-beam is cooled. The four kinds of cooling scheme are designed. Through analysis of the relation of temperature field with stress field, the main reason of producing residual thermal stress is the section temperature difference in the cooling process of H-beam after rolling.


2011 ◽  
Vol 464 ◽  
pp. 405-408
Author(s):  
Gao Lian Shi ◽  
Shi Hong Shi ◽  
Shao Hua Wu ◽  
Yong Kang Wang

Aimed at the process of laser rapid prototyping with inner coaxial powder feeding, the finite element model on the transient temperature field of the molten pool is built and the transient temperature field of the molten pool under the laser with variable duty ratio is simulated numerically. The results show that the duty ratio of the laser affects the shape, dimension and power distribution of the molten pool. With the processing parameters: laser power (P)=3000W, outer diameter(d2)=4mm, scanning speed(V=5mm/s), the ideal value of ratio duty(K) is from 0.35 to 0.6. The shape of the molten pool is saddle shape or crescent. The position of the molten pool falls behind the center of the laser beam with the deviation to the both sides. Through shooting the molten pool with the high speed CCD camera, we find the experiments show that the images are close to the numerical simulation nephograms and then demonstrate that the numerical simulations are right.


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