scholarly journals Determination of cable tensile forces using paraseismic effects

2020 ◽  
Vol 310 ◽  
pp. 00019
Author(s):  
Daniel Papán ◽  
Zuzana Papánová
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Dynamic Equations ◽  
Civil Structures ◽  
Load Bearing ◽  
Tensile Forces

By construction or by reconstruction of civil structures can be paraseismic load generated. This effect may causes cracks in buildings standing near the source of the vibrations. Numerical simulation is one of the possibilities how can be this problem analyzed. The vibrations velocities of source transmitted to the surrounding buildings can be used as excitation to the numerical simulations. In the paper is presented the case study of the assessment of the tension forces in load bearing cables in real civil structure. This estimation is based on theoretical and experimental dynamic equations comparison.

Numerical Simulation of Offshore Pipeline Installation by Lateral Deflection Procedure

2007 ◽  
Author(s):  
Danilo Machado Lawinscky da Silva ◽  
Rodrigo Almeida Bahiense ◽  
Breno Pinheriro Jacob ◽  
Fernando Gomes da Silva Torres ◽  
Antonio Roberto Medeiros ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Computational Tool ◽  
Lateral Deflection ◽  
Correct Definition ◽  
Offshore Pipeline ◽  
Definition Of

Conventional offshore pipeline installation operations in Brazil have been performed in an S-Lay procedure employing the BGL-1 barge, owned by Petrobras. However, this procedure has some limits, and may not be feasible in some particular scenarios. Therefore, the objective of this work is to present the numerical simulation of an alternative pipeline installation procedure. This procedure basically consists of performing the pipeline assembly on shore, and deflecting it to the sea using a tug boat. The numerical simulations employ the SITUA-Prosim computational tool, which is able to incorporate the correct definition of the seabed and shore from bathymetric curves. An actual pipeline installation by this lateral deflection procedure is analyzed and discussed. The characterization of the procedure passes through the determination of the better velocity and direction of the tug boat in order to minimize the efforts on the pipeline (especially due to the curvatures).

scholarly journals Determination of Stability Correction Parameters for Dynamic Equations of Constrained Multibody Systems

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Lyu Guizhi ◽  
Liu Rong
Keyword(s):  
Numerical Simulation ◽  
Constraint Equation ◽  
System Stability ◽  
Dynamic Equations ◽  
Constraint Violation ◽  
Stability Parameters ◽  
Constraint Matrix ◽  
Stability Method ◽  
Parameter Values

When analyzing mechanical systems with numerical simulation by the Udwadia and Kalaba method, numerical integral results of dynamic equations will gradually deviate from requirements of constraint equations and eventually lead to constraint violation. It is a common method to solve the constraint violation by using constraint stability to modify the constraint equation. Selection of stability parameters is critical in the particular form of the corrected equation. In this paper, the method of selecting and determining of stability parameters is given, and these parameters will be used to correct the Udwadia-Kalaba basic equation by the Baumgarte constraint stability method. The selection domain of stability parameters is further reduced in view of the singularity of the constraint matrix during the integration procedure based on the selection domain which is obtained by the system stability analysis method. Errors of velocity violation and position violation are defined in the workspace, so as to determine the parameter values. Finally, the 3-link spatial manipulator is used to verify stability parameters of the proposed method. Numerical simulation results verify the effectiveness of the proposed method.

Determination of Interlaminar Fracture Toughness of CFRP Composite in Mode I Using Numerical Simulation with Cohesive Elements

2020 ◽  
Vol 847 ◽  
pp. 15-21
Author(s):  
Frantisek Sedlacek ◽  
Tomas Kalina ◽  
Karel Raz
Keyword(s):  
Numerical Simulation ◽  
Fracture Toughness ◽  
Numerical Simulations ◽  
Analytical Calculation ◽  
Mode I ◽  
Experimental Measurements ◽  
Cohesive Elements ◽  
Cohesive Failure ◽  
Cfrp Composite

This paper deals with the determination of parameters of the interlaminar failure of the CFRP composite laminate in mode I using numerical simulation with cohesive elements. Knowledge of these parameters is crucial to enable prediction of interlaminar strength of laminates using numerical simulations based on the finite element method with cohesive elements. There are several standardized experimental measurements for determining mode I parameters but not all that are needed for numerical simulations. However, the determination of these parameters and their evolution during cohesive failure is very problematic even if the experimental data is available. This paper deals with the design of a methodology for how to determine these parameters using the fitting process of experimental measurement and numerical simulation. The experimental measurements were done on double cantilever beam specimens according to ASTM standards. The numerical simulations were performed in the Siemens Simcenter software with NX Nastran solver. The numerical model with the obtained parameters shows very good agreement with the experimental measurements. compared to the average experimental values and the analytical calculation, the difference of fracture toughness is up to 1.6 %

scholarly journals Numerical Simulation of the Hydrodynamics of Some Sectors of the Prute River

2019 ◽  
Vol 70 (3) ◽  
pp. 902-905
Author(s):  
Galina Marusic ◽  
Valeriu Panaitescu
Keyword(s):  
Water Pollution ◽  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Flow Characteristics ◽  
Aquatic Systems ◽  
Cfd Analysis ◽  
Computational Fluid Dynamics Cfd ◽  
Prut River

This paper addresses issues related to the determination of hydrodynamics of aquatic systems, with the application of computational fluid dynamics (CFD) analysis. The importance of knowing the hydrodynamics of aquatic systems for solving water pollution problems, as well as their prevention, is discussed. A case study regarding the determination of the water flow characteristics using CFD for some sectors of the Prut river is presented.

scholarly journals Paraseismic effects of the fundamental structure dynamic simulation

2021 ◽  
Vol 352 ◽  
pp. 00014
Author(s):  
Branislav Valent ◽  
Martin Ščotka
Keyword(s):  
Numerical Simulations ◽  
Dynamic Simulation ◽  
Critical Values ◽  
National Standards ◽  
Civil Structures ◽  
The Real ◽  
Fundamental Structure ◽  
Structure Dynamic

The paraseismic effect due to civil structures construction may cause cracks in buildings around the source of the vibration. The vibrations velocities of the source transmitted to the surrounding buildings can be used as excitation to the numerical simulations. In the paper the case study of the assessment of the real civil structure dynamic simulation is presented. The response is evaluated and compared to the critical values in national standards.

scholarly journals DETERMINATION OF THE WALL VARIABLES WITHIN THE ZONAL MODEL OF RADIATION INSIDE A PULVERIZED COAL-FIRED FURNACE

2018 ◽  
Vol 16 (2) ◽  
pp. 219 ◽  
Author(s):  
Nenad Crnomarković ◽  
Srđan Belošević ◽  
Stevan Nemoda ◽  
Ivan Tomanović ◽  
Aleksandar Milićević
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Extinction Coefficient ◽  
Heat Fluxes ◽  
Pulverized Coal ◽  
Arithmetic Means ◽  
Zonal Model ◽  
Relative Differences ◽  
Total Exchange

Determination of the wall variables (wall emissivities, wall temperatures, and heat fluxes) when the zonal model of radiation is used in numerical simulations of processes inside a pulverized coal-fired furnaces is described. Two methods for determination of the wall variables, i.e., a repeated run of numerical simulation (RRNS) and a temporary correction of the total exchange areas (TCTEA) are compared. Investigation was carried out for three values of the flame total extinction coefficient and four values of the initial wall emissivities. Differences of the wall variables were determined using the arithmetic means (AMs) of the relative differences. The AMs of the relative differences of the wall variables increased with an increase in the flame total extinction coefficient and changed a little with an increase in the initial values of the wall emissivities. For the selected furnace, the smallest differences of the wall variables were obtained for Kt=0.3 m-1 and ew,in=0.7. Although both methods can be used for determination of the wall variables, the RRNS method was recommended because the manipulation with files was easier for it. mmended because the manipulation with files was easier for it.

A novel method for the determination of linting propensity of paper

TAPPI Journal ◽  
2012 ◽  
Vol 11 (10) ◽  
pp. 9-17
Author(s):  
ALESSANDRA GERLI ◽  
LEENDERT C. EIGENBROOD
Keyword(s):  
Ash Content ◽  
The Novel ◽  
Offset Printing ◽  
Excellent Correlation ◽  
End Conditions ◽  
Bottom Side ◽  
Novel Method ◽  
Total Fraction

A novel method was developed for the determination of linting propensity of paper based on printing with an IGT printability tester and image analysis of the printed strips. On average, the total fraction of the surface removed as lint during printing is 0.01%-0.1%. This value is lower than those reported in most laboratory printing tests, and more representative of commercial offset printing applications. Newsprint paper produced on a roll/blade former machine was evaluated for linting propensity using the novel method and also printed on a commercial coldset offset press. Laboratory and commercial printing results matched well, showing that linting was higher for the bottom side of paper than for the top side, and that linting could be reduced on both sides by application of a dry-strength additive. In a second case study, varying wet-end conditions were used on a hybrid former machine to produce four paper reels, with the goal of matching the low linting propensity of the paper produced on a machine with gap former configuration. We found that the retention program, by improving fiber fines retention, substantially reduced the linting propensity of the paper produced on the hybrid former machine. The papers were also printed on a commercial coldset offset press. An excellent correlation was found between the total lint area removed from the bottom side of the paper samples during laboratory printing and lint collected on halftone areas of the first upper printing unit after 45000 copies. Finally, the method was applied to determine the linting propensity of highly filled supercalendered paper produced on a hybrid former machine. In this case, the linting propensity of the bottom side of paper correlated with its ash content.

The Calculation of Turbulent Diffusion Coefficients in Aquatic Ecosystems

2019 ◽  
Vol 70 (11) ◽  
pp. 3903-3907
Author(s):  
Galina Marusic ◽  
Valeriu Panaitescu
Keyword(s):  
Transport Equation ◽  
Turbulent Diffusion ◽  
Diffusion Coefficients ◽  
Aquatic Ecosystems ◽  
Specific Area ◽  
Left Bank ◽  
The Right ◽  
Prut River

The paper deals with the issues related to the pollution of aquatic ecosystems. The influence of turbulence on the transport and dispersion of pollutants in the mentioned systems, as well as the calculation of the turbulent diffusion coefficients are studied. A case study on the determination of turbulent diffusion coefficients for some sectors of the Prut River is presented. A new method is proposed for the determination of the turbulent diffusion coefficients in the pollutant transport equation for specific sectors of a river, according to the associated number of P�clet, calculated for each specific area: the left bank, the right bank and the middle of the river.

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