Large-Scale Numerical Analysis of Three-Dimensional Seismic Waves.

Author(s):  
G. L. Wojcik ◽  
D. K. Vaughan
2020 ◽  
Vol 19 (4) ◽  
pp. 855-873
Author(s):  
Zhongxian Liu ◽  
Ce Shang ◽  
Lei Huang ◽  
Jianwen Liang ◽  
Jie Li

1996 ◽  
Vol 12 (04) ◽  
pp. 269-275
Author(s):  
Panagiotis Michaleris ◽  
Andrew DeBiccari

This paper presents an efficient and effective numerical analysis technique for predicting welding-induced buckling. The technique combines three-dimensional structural analyses with two-dimensional welding simulations. Implementation of the technique can determine the appropriate welding conditions under which the design critical buckling load is not exceeded. Experimental results obtained from small-and large-scale mock-up panels are used to confirm the predictions of the analytical models, The paper concludes with a study of the effects of heat input (weld size), panel size, and panel thickness on buckling distortion.


Author(s):  
Tadashi Tanuma ◽  
Yasuhiro Sasao ◽  
Satoru Yamamoto ◽  
Yoshiki Niizeki ◽  
Naoki Shibukawa ◽  
...  

The purpose of this paper is to present the methodology for high accurate aerodynamic numerical analysis and its design application of steam turbine down-flow type exhaust diffusers including their three dimensional flow interaction effects on last stage efficiencies. Down-flow type exhaust diffusers are used in large scale steam turbines from 200MW to 1400MW class units for power generation plants mainly. The axial length of typical 1000MW class large scale steam turbines is about 30–40m and its four low pressure (LP) down-flow type exhaust diffusers occupy a large amount of space. The axial lengths and diameters of these exhaust diffusers contribute significantly to the size, weight, cost, and efficiency of the turbine system. The aerodynamic loss of exhaust hoods is nearly the same as that of stator and rotor blading in LP steam turbines, and there remains scope for further enhancement of steam turbine efficiency by improving the design of LP exhaust hoods. In the design process of last stages, the average static pressure in the last stage exit is introduced accurately using numerical analysis and experimental data of model steam turbines and model diffusers. However the radial and circumferential unsteady aerodynamic interaction effects between last stages and their exhaust diffusers are still need to be investigated to increase the accuracy of the interaction effect on the last stage efficiencies. This paper presents numerical investigation of three dimensional wet steam flows including three dimensional flow interaction effects on last stage efficiencies in a down-flow type exhaust diffuser with non-uniform inlet flow from a typical last stage with long transonic blades designed with recent aerodynamic and mechanical design technology.


2014 ◽  
Vol 1065-1069 ◽  
pp. 426-432
Author(s):  
Shi Kui Huang ◽  
Jie Zhao

For a nuclear power intake tunnel project, large-scale three-dimensional finite difference model is established by Flac3D to simulate the seismic response regularity of the entrance section of tunnel under the action of seismic waves schedule with the nonlinear dynamic analysis method. Through the input of the site seismic wave, the structure response characteristics of the tunnel entrance and slope are explored and duration curve of tunnel hole lining force under seismic waves action and tunnel lining figure can be obtained. The analysis results show that the anti-seismic weak parts of the tunnel entrance is at the location of tunnel spandrel and the sidewall. The analysis method and conclusions can be for reference in the seismic design of similar nuclear power intake tunnel project.


Author(s):  
Emre Bulut ◽  
Gökhan Sevilgen ◽  
Ferdi Eşiyok ◽  
Ferruh Öztürk ◽  
Tuğçe Turan Abi

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