scholarly journals The Analysis of Steel Girder Damage Mechanism in Hyogoken-Nanbu Earthquake and Verification of Countermeasures for Seismic Safety.

2002 ◽  
pp. 31-43
Author(s):  
Kiichiro YAMAHIRA ◽  
Hisanori OTSUKA
Keyword(s):  
Damage Mechanism ◽  
Steel Girder ◽  
Seismic Safety

Study on Seismic Safety Improvement of Hanging Type Mechanical Structure in Industrial Facilities During Long Duration Earthquake

2015 ◽  
Author(s):  
Osamu Furuya ◽  
Kazuhiro Yoshida ◽  
Sho Asaoka ◽  
Keiji Ogata ◽  
Nobuhiro Niiyama
Keyword(s):  
Shaking Table Test ◽  
Low Cycle Fatigue ◽  
Damage Mechanism ◽  
Shaking Table ◽  
Experimental Result ◽  
Seismic Safety ◽  
Industrial Facilities ◽  
Mechanical Structure ◽  
Secondary Damage ◽  
Safety Improvement

A lot of seismic damages of hanging type mechanical structure in industrial facilities were occurred in Great East Japan Earthquake, and the industrial functions stopped at many facilities. Moreover, fallen damage of mechanical structures from a hanging in architectural structure and the falling off of some elements in mechanical structures caused a secondary damage such as severed evacuation route. This study has been carried out to upgrade the seismic safety improvement of hanging type mechanical structure in several industrial and plant facilities from analytical and experimental approaches. In this paper, the experimental result in shaking table test is shown to investigate fallen mechanism of hanging type mechanical structure, and analytical results using nonlinear model with hysteresis damping is described. Furthermore, the evaluation of damage mechanism based on low cycle fatigue damage is conducted.

Elemental mass loss in silicate minerals during x-ray analysis

1990 ◽  
Vol 48 (4) ◽  
pp. 804-805
Author(s):  
P.E. Champness ◽  
R.W. Devenish
Keyword(s):  
Mass Loss ◽  
Current Density ◽  
Damage Mechanism ◽  
Beam Current ◽  
Single Chain ◽  
Plagioclase Feldspar ◽  
X Ray ◽  
Alkali Ions ◽  
Structural Order ◽  
Sheet Silicate

It has long been recognised that silicates can suffer extensive beam damage in electron-beam instruments. The predominant damage mechanism is radiolysis. For instance, damage in quartz, SiO2, results in loss of structural order without mass loss whereas feldspars (framework silicates containing Ca, Na, K) suffer loss of structural order with accompanying mass loss. In the latter case, the alkali ions, particularly Na, are found to migrate away from the area of the beam. The aim of the present study was to investigate the loss of various elements from the common silicate structures during electron irradiation at 100 kV over a range of current densities of 104 - 109 A m−2. (The current density is defined in terms of 50% of total current in the FWHM probe). The silicates so far ivestigated are:- olivine [(Mg, Fe)SiO4], a structure that has isolated Si-O tetrahedra, garnet [(Mg, Ca, Fe)3Al2Si3AO12 another silicate with isolated tetrahedra, pyroxene [-Ca(Mg, Fe)Si2O6 a single-chain silicate; mica [margarite, -Ca2Al4Si4Al4O2O(OH)4], a sheet silicate, and plagioclase feldspar [-NaCaAl3Si5O16]. Ion- thinned samples of each mineral were examined in a VG Microscopes UHV HB501 field- emission STEM. The beam current used was typically - 0.5 nA and the current density was varied by defocussing the electron probe. Energy-dispersive X-ray spectra were collected every 10 seconds for a total of 200 seconds using a Link Systems windowless detector. The thickness of the samples in the area of analysis was normally 50-150 nm.

Experimental Study and Numerical Simulation for Explosion and Phenomena of RC Slabs

2014 ◽  
Vol 501-504 ◽  
pp. 1096-1103
Author(s):  
Hong Xiao Wu ◽  
Hao Zhe Xing ◽  
Zhi Fang Yan
Keyword(s):  
Reinforced Concrete ◽  
Impact Loading ◽  
Loading Condition ◽  
Damage Mechanism ◽  
Failure Characteristics ◽  
Explosion Pressure ◽  
Concrete Plate ◽  
Solid Models ◽  
Calculation Results ◽  
Rc Slabs

The blast impact dynamic experiment of reinforced concrete rectangular plate with simply supported boundary conditions was performed using explosion pressure simulator. With 3-D FEM software LS-DYNA, the separate solid models of concrete and steel were established and 3-D FEM dynamic analysis of the experiment process was carried out. Compared calculation results to experiment results synthetically, the damage mechanism and failure characteristics of reinforced concrete plate under explosion impact loading condition were got and it is also verified that the H-J-C model can approximately simulate the concrete properties well under explosion impact loading condition.

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