Choice of numerical model as a key point of holographic interferometry data implementing for hybrid strain/stress analysis

1999 ◽  
Author(s):  
Karl-Hans Laermann ◽  
Vladimir S. Pisarev ◽  
Vladimir D. Grigoriev
Keyword(s):  
Numerical Model ◽  
Stress Analysis ◽  
Holographic Interferometry ◽  
Hybrid Strain ◽  
Strain Stress

Seismic Base Isolation Using Natural Materials - Experimental and Numerical Verification

2021 ◽  
Author(s):  
◽  
Ivan Banović
Keyword(s):  
Numerical Model ◽  
Seismic Isolation ◽  
Base Isolation ◽  
Seismic Analysis ◽  
Model Parameters ◽  
Seismic Force ◽  
Strain Stress ◽  
Limestone Sand ◽  
Seismic Base Isolation ◽  
Model Failure

The problem under consideration is the earthquake impact on structures. The subject of the performed research is the efficiency of seismic base isolation using layers of predominantly natural materials below the foundation, as well as the development of a numerical model for seismic analysis of structures with such isolation. The aseismic layers below foundation are made of limestone sand - ASL-1, stone pebbles - ASL-2, and stone pebbles combined with layers of geogrid and geomembrane - ASL-3. The experimental research methodology is based on the use of shake-table and other modern equipment for dynamic and static testing of structures. Experiments were conducted on the basis of detailed research plan and program. Efficiency of the limestone sand layer - ASL-1 was tested on cantilever concrete columns, under seismic excitations up to failure, varying the sand thickness and intensity of seismic excitation. Influence of several layer parameters on the efficiency of stone pebble layer - ASL-2 was investigated. For each considered layer parameter, a rigid model M0 was exposed to four different accelerograms, with three levels of peak ground acceleration (0.2 g, 0.4 g and 0.6 g), while all other layer parameters were kept constant. On the basis of test results, the optimal pebble layer was adopted. Afterwards, the optimal ASL-2 efficiency was tested on various model parameters: stiffness (deformable models M1-M4), foundation size (small and large), excitation type (four earthquake accelerograms), and stress level in the model (elastic and up to failure). In the ASL-3 composite aseismic layer, the optimal ASL-2 is combined with a thin additional layer of sliding material (geogrid, geomembrane above limestone sand layer), in order to achieve greater efficiency of this layer than that of the ASL-2. A total of eleven different aseismic layers were considered. To determine the optimal ASL-3, the M0 model was used, like for the ASL-2. On the basis of test results, the optimal ASL-3 layer was adopted (one higher strength geogrid at the pebble layer top). The optimal ASL-3 is tested on various model parameters, analogous to the optimal ASL-2. A numerical model for reliable seismic analysis of concrete, steel, and masonry structures with seismic base isolation using ASL-2 was developed, with innovative constitutive model for seismic isolation. The model can simulate the main nonlinear effects of mentioned materials, and was verified on performed experimental tests. In relation to the rigid base - RB without seismic isolation, model based on the ASL-1 had an average reduction in seismic force and strain/stress by approximately 10% at lower PGA levels and approximately 14% at model failure. Due to the effect of sand calcification over time, the long-term seismic efficiency of such a layer is questionable. It was concluded that the aseismic layers ASL-2 and ASL-3 are not suitable for models of medium-stiff structure M3 and soft structure M4. In relation to the RB without seismic isolation, the M1 (very stiff structure) and M2 (stiff structure) based on the ASL-2 had an average reduction in seismic force and strain/stress by approximately 13% at lower PGA levels and approximately 25% at model failure. In relation to the RB without seismic isolation, the M1 and M2 based on the ASL-3 had an average reduction in seismic force and strain/stress by approximately 25% at lower PGA levels and approximately 34% at model failure. In relation to the RB without seismic isolation, the ASL-2 and ASL-3 did not result in major M1 and M2 model displacements, which was also favourable. It is concluded that the ASL-2 and especially ASL-3 have great potential for seismic base isolation of very stiff and stiff structures, as well as small bridges based on solid ground, but further research is needed. In addition, it was concluded that the developed numerical model has great potential for practical application. Finally, further verification of the created numerical model on the results of other experimental tests is needed, but also improvement of the developed constitutive models.

Microstructure and strain-stress analysis of the dynamic strain aging in inconel 625 at high temperature

2017 ◽  
Vol 23 (1) ◽  
pp. 54-67 ◽  
Author(s):  
P. Maj ◽  
J. Zdunek ◽  
J. Mizera ◽  
K. J. Kurzydlowski ◽  
B. Sakowicz ◽  
...  
Keyword(s):  
High Temperature ◽  
Stress Analysis ◽  
Dynamic Strain Aging ◽  
Strain Aging ◽  
Inconel 625 ◽  
Dynamic Strain ◽  
Strain Stress

Study on Reliability Assessment and Mechanics Behavior of Slab Culvert under Heavy Train

2011 ◽  
Vol 90-93 ◽  
pp. 1157-1161
Author(s):  
Qi Cai Wang ◽  
Rong Ling Zhang ◽  
Li Na Ma ◽  
You Xing Wei
Keyword(s):  
Fatigue Life ◽  
Corrosion Rate ◽  
Stress Analysis ◽  
Fatigue Test ◽  
Failure Probability ◽  
Reliability Assessment ◽  
Heavy Haul Train ◽  
Starting Point ◽  
Heavy Haul ◽  
Strain Stress

Abstract：The paper takes heavy haul train existing slab culvert disease and the research status for starting point, researches and analyzes the reliability assessment of slab culvert and fatigue test under heavy haul train. Different corrosion rate and reinforced section failure probability and reliable probability relations is researched as the emphasis . Strain-stress relations and slab culvert reinforced load are studied by the fatigue test , drawn the fatigue life of tensile steel. The research provides a reference for the stress analysis of slab culvert under the point supported conditions.

scholarly journals The legal and technical possibilities of using of scaffoldings as the ramp for disabled persons

2015 ◽  
Vol 14 (1) ◽  
pp. 005-014
Author(s):  
Ewa Błazik-Borowa ◽  
Michał Pieńko ◽  
Aleksander Robak
Keyword(s):  
Numerical Analysis ◽  
Numerical Model ◽  
Stress Analysis ◽  
Static Analysis ◽  
Disabled Persons ◽  
Technical Documentation ◽  
System Components ◽  
The Disabled ◽  
Computer Calculations ◽  
Dynamic Impacts

The paper is devoted to the problems of legal and technical making the ramp for disabled persons with scaffolds. Scaffolding system components allow you to assemble a structure that serve as the ramp and fulfil the requirements of technical conditions. From a legal point the most important is the fact that the ramp construction needs a building application. In this regard, the greatest problems is obtaining the rights to use the property for construction purposes. A big challenge is to also perform stress analysis, taking into account of dynamic impacts caused by the movement of the trolley. In this regard, the paper presents a numerical model of the ramp, static analysis, modal analysis and results of prediction of a disabled person ride on the trolley. The results of computer calculations have shown that the construction of the ramp requires the exact numerical analysis. Therefore, the best option would be in order to scaffolding companies will prepare relevant technical documentation of products which are ramps for the disabled.

scholarly journals STRAIN-STRESS ANALYSIS OF GEAR COUPLING

2020 ◽  
Author(s):  
R. Vondra ◽  
K. Rehak ◽  
A. Prokop
Keyword(s):  
Stress Analysis ◽  
Strain Stress
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