Numerical Simulation Technique of Disks Skipping Based on the SPH Method

2014 ◽  
Vol 668-669 ◽  
pp. 494-498
Author(s):  
Yong Hu Wang ◽  
Cai Hua Chen ◽  
Ting Yu Zhao ◽  
Wei Hu
Keyword(s):  
Numerical Simulation ◽  
Boundary Condition ◽  
Boundary Conditions ◽  
Simulation Technique ◽  
Contrastive Analysis ◽  
Sph Method ◽  
Different Boundary Conditions ◽  
The Future ◽  
Numerical Simulation Technique

It is significant for the phenomena of bouncing on water to analyze the ditching procedure of any kind of aircraft. The SPH method is employed to achieve a numerical simulation in the architecture of LS-DYNA and PrePost programs. The water domain is modeled by SPH and the boundary condition is discussed too. Through a set of contrastive analysis of different boundary conditions, some constructive suggestions of establishing the boundary conditions are given to deeply simulate aircraft ditching in the future.

Strength of Surface Micromachined Diaphragms

1998 ◽  
Vol 518 ◽  
Author(s):  
Xing Yang ◽  
Frances M. Siu ◽  
Yu-Chong Tai
Keyword(s):  
Boundary Condition ◽  
Silicon Nitride ◽  
Boundary Conditions ◽  
Fabrication Process ◽  
Surface Micromachining ◽  
Fabrication Technique ◽  
Different Boundary Conditions ◽  
The Common

AbstractThis paper presents the study of the strength of surface micromachined diaphragms. It is found that the diaphragm strength strongly depends on the diaphragm boundary conditions. A new fabrication technique which does not change the mask and fabrication process is proposed to improve the common step-up boundary condition. Test diaphragms with diameters from 200 µm to 800 µm and three different boundary conditions have been fabricated using silicon nitride/PSG and silicon nitride/polysilicon surface micromachining processes. Experimentally, it is found that the strength of the diaphragms is significantly improved with the new boundary conditions. The application of this technique to other surface micromachined structures is also described.

scholarly journals Effects of Boundary Condition Models on the Seismic Responses of a Container Crane

2019 ◽  
Vol 9 (2) ◽  
pp. 241 ◽  
Author(s):  
Jungwon Huh ◽  
Van Nguyen ◽  
Quang Tran ◽  
Jin-Hee Ahn ◽  
Choonghyun Kang
Keyword(s):  
Boundary Condition ◽  
Boundary Conditions ◽  
Time History ◽  
Dynamic Responses ◽  
Seismic Excitation ◽  
Different Boundary Conditions ◽  
Container Crane ◽  
Condition Model ◽  
Boundary Condition Model ◽  
Significant Difference

In recent years, several large earthquakes have caused the collapse of container cranes, which have resulted in halting of freighting, and significantly affected the economy. Some reports are concerned the uplift and derailment events of crane legs, and the collapse of the crane itself. In this study, the effects of different boundary conditions used in the numerical method are investigated for a container crane under seismic excitation. Three different boundary conditions are considered in terms of the connection of the crane’s legs (wheels) and the ground (rails), namely pin support (PIN), gap element (GAP), and Friction contact (FC) elements, by using the SAP2000 program for a typical container crane. Then, time history dynamic analyses are conducted using nine recorded ground motions. Dynamic behaviors of the container crane are studied in terms of the total base shear, portal drift, and relative displacement of legs, by investigating the three types of base boundary conditions. The results of the study show that when the intensity of earthquakes is large enough to create uplift and derailment events, the selection of the boundary condition model considerably affects the dynamic responses of the container crane. In addition, when uplift and derailment of the crane occur, the FC support condition is the most compatible with the real behavior of the crane. On the other hand, under low seismic excitation, there is no significant difference of the crane behavior according to the choice of boundary condition model.

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