Development of base oscillation models and regulatory approaches to the calculation of critical structures for seismic impacts

2020 ◽  
pp. 32-54
Author(s):  
I. I. Vedyakov ◽  
V. K. Vostrov
Keyword(s):  
Bearing Capacity ◽  
Emergency Situation ◽  
Seismic Loads ◽  
Construction Site ◽  
Resonant Vibrations ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Earthquake Resistant ◽  
Base Oscillation ◽  
Seismic Impacts

Two principal approaches to generating calculated seismic impacts, proposed in the practice of earthquake - resistant construction, were used and refined: for the construction site and for the structure. There are special, emergency and extreme seismic loads that create an emergency situation - the occurrence of a mode of beats or resonant vibrations, as well as self-oscillations (acute resonance), leading to a violation of either the operational properties or the load-bearing capacity of the structure. Proposals are formulated for the revision of the Russian standards of earthquake-resistant construction, based on three-level impact for responsible and unique structures using the proposed refined approaches to generating calculated seismic impacts.

Development of models of vibrations of critical structures and regulatory approaches to calculations for seismic impacts

2021 ◽  
pp. 18-37
Author(s):  
Ivan I. Vedyakov ◽  
Vladimir K. Vostrov
Keyword(s):  
Parametric Resonance ◽  
Nonlinear Vibrations ◽  
Emergency Situation ◽  
Seismic Loads ◽  
Loss Of Stability ◽  
Resonant Vibrations ◽  
Earthquake Resistant ◽  
The Stability ◽  
New Generation ◽  
Seismic Impacts

The calculation of the stability of the equilibrium position required by the canceled and current norms of earthquake-resistant construction, and the calculation of the dynamic stability of various partial movements, the requirements for the necessity of which are absent both in the proposals for the norms of the new generation and in the current norms of earthquake-resistant construction, are the main ones in the calculation and design of structures taking into account their interaction with the base. Special and emergency seismic loads are identified that create an emergency situation − the occurrence of a mode of beating or resonant vibrations, as well as parametric resonance and nonlinear vibrations that occur after the loss of stability of the position of structures.

Comparison Experimental Tests of Behavior of the Slab-Column Structure after Removal of the Corner Support with Simplified Models Describing the Mechanism of Destruction

2014 ◽  
Vol 969 ◽  
pp. 78-84 ◽  
Author(s):  
Mirosław Wieczorek
Keyword(s):  
Bearing Capacity ◽  
Emergency Situation ◽  
Experimental Tests ◽  
Simplified Models ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Boundary State ◽  
Column Structure

The paper deals with the boundary state of the load-bearing capacity of a fragment of a slab-column structure in an emergency situation caused by the removal of a support at its corner. The paper presents the results of tests concerting the investigated element with the dimensions of 4000×4000×100 mm. Next, theoretically suggested mechanisms of the corner support have been dealt with, describing the behaviour of a slab-column structure after the removal of the support at the corner. The aim of the paper was to compare the results of test carried out in the laboratory with the values obtained by analytical calculations. The results of this analysis have been gathered in the summary.

Increased load bearing capacity of mechanically joined FRP/metal joints using a pin structured auxiliary joining element

2020 ◽  
Vol 62 (1) ◽  
pp. 55-60
Author(s):  
Per Heyser ◽  
Vadim Sartisson ◽  
Gerson Meschut ◽  
Marcel Droß ◽  
Klaus Dröder
Keyword(s):  
Bearing Capacity ◽  
Load Bearing Capacity ◽  
Load Bearing

Load-Bearing Capacity of Direct Inlay-Retained Fibre-reinforced Composite Fixed Partial Dentures with Different Cross-Sectional Pontic Design

2017 ◽  
Vol 68 (1) ◽  
pp. 94-100
Author(s):  
Oana Tanculescu ◽  
Adrian Doloca ◽  
Raluca Maria Vieriu ◽  
Florentina Mocanu ◽  
Gabriela Ifteni ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Fracture Pattern ◽  
Load Bearing Capacity ◽  
Cross Sectional ◽  
Load Bearing ◽  
Reinforced Composite ◽  
Polyethylene Fibre

The load-bearing capacity and fracture pattern of direct inlay-retained FRC FDPs with two different cross-sectional designs of the ponticwere tested. The aim of the study was to evaluate a new fibre disposition. Two types of composites, Filtek Bulk Fill Posterior Restorative and Filtek Z250 (3M/ESPE, St. Paul, MN, USA), and one braided polyethylene fibre, Construct (Kerr, USA) were used. The results of the study suggested that the new tested disposition of the fibres prevented in some extend the delamination of the composite on buccal and facial sides of the pontic and increased the load-bearing capacity of the bridges.

scholarly journals The energy absorption behavior of novel composite sandwich structures reinforced with trapezoidal latticed webs

2021 ◽  
Vol 60 (1) ◽  
pp. 503-518
Author(s):  
Juan Han ◽  
Lu Zhu ◽  
Hai Fang ◽  
Jian Wang ◽  
Peng Wu
Keyword(s):  
Bearing Capacity ◽  
Energy Absorption ◽  
Sandwich Structure ◽  
Ultimate Load ◽  
Sandwich Structures ◽  
Elastic Displacement ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Composite Sandwich ◽  
Composite Sandwich Structures

Abstract This article proposed an innovative composite sandwich structure reinforced with trapezoidal latticed webs with angles of 45°, 60° and 75°. Four specimens were conducted according to quasi-static compression methods to investigate the compressive behavior of the novel composite structures. The experimental results indicated that the specimen with 45° trapezoidal latticed webs showed the most excellent energy absorption ability, which was about 2.5 times of the structures with vertical latticed webs. Compared to the traditional composite sandwich structure, the elastic displacement and ultimate load-bearing capacity of the specimen with 45° trapezoidal latticed webs were increased by 624.1 and 439.8%, respectively. Numerical analysis of the composite sandwich structures was carried out by using a nonlinear explicit finite element (FE) software ANSYS/LS-DYNA. The influence of the thickness of face sheets, lattice webs and foam density on the elastic ultimate load-bearing capacity, the elastic displacement and initial stiffness was analyzed. This innovative composite bumper device for bridge pier protection against ship collision was simulated to verify its performance. The results showed that the peak impact force of the composite anti-collision device with 45° trapezoidal latticed webs would be reduced by 17.3%, and the time duration will be prolonged by about 31.1%.

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