The consideration of compliance of structural joints in calculation of large panel buildings

The article presents and analyzes the design solutions of horizontal and vertical joints, as well as methods for determining the coefficient of compliance joints. It also presents the numerical determination of the coefficients of compliance of the horizontal mortar joint in accordance with the standards for the design of large-panel buildings. It is shown that the compliance of the joint on the embedded parts consists of the compliance of the connecting element, embedded parts of the wall panels, namely the metal plate and reinforcing bars of the anchors, as well as the compliance of the welds. In this case, the joint operates in a complex stress-strain state. It is noted that the most difficult is to determine the compliance of embedded parts. Three calculation methods have been developed for the numerical determination of the compliance coefficients of anchor bars under the action of tension (compression), bending moment and shear forces on the embedded part. The deformation of the welds was defined in MGSU in the framework of the experimental research of the work of the vertical seam with embedded parts. The article presents a graph of the deformation in the weld on the applied vertical load on the test piece.

Download Full-text

Numerical determination of surface temperature for in-depth thermocouples

10.2514/6.1984-1763 ◽

1984 ◽

Author(s):

D. JONES ◽

D. PATEL ◽

E. ALEXANDER

Keyword(s):

Surface Temperature ◽

Numerical Determination

Download Full-text

The Influence of Loads Superposition, Deterioration Due to Cracks and Residual Stresses on the Strength of Tubular Junction

Revista de Chimie ◽

10.37358/rc.17.6.5655 ◽

2017 ◽

Vol 68 (6) ◽

pp. 1267-1273

Author(s):

Valeriu V. Jinescu ◽

Angela Chelu ◽

Gheorghe Zecheru ◽

Alexandru Pupazescu ◽

Teodor Sima ◽

...

Keyword(s):

Stress Concentration ◽

Residual Stresses ◽

Bending Moment ◽

Combined Loading ◽

Torsional Moment ◽

Calculation Methods ◽

State Of Stress ◽

Cracked Structures ◽

Total Participation ◽

Theoretical Results

In the paper the interaction of several loads like pressure, axial force, bending moment and torsional moment are analyzed, taking into account the deterioration due to cracks and the influence of residual stresses. A nonlinear, power law, of structure material is considered. General relationships for total participation of specific energies introduced in the structure by the loads, as well as for the critical participation have been proposed. On these bases: - a new strength calculation methods was developed; � strength of tubular cracked structures and of cracked tubular junction subjected to combined loading and strength were analyzed. Relationships for critical state have been proposed, based on dimensionless variables. These theoretical results fit with experimental date reported in literature. On the other side stress concentration coefficients were defined. Our one experiments onto a model of a pipe with two opposite nozzles have been achieved. Near one of the nozzles is a crack on the run pipe. Trough the experiments the state of stress have been obtained near the tubular junction, near the tip of the crack and far from the stress concentration points. On this basis the stress concentration coefficients were calculated.

Download Full-text

Experimental and Numerical Determination of Micropropulsion Device Efficiencies at Low Reynolds Numbers

10.21236/ada432073 ◽

2004 ◽

Cited By ~ 1

Author(s):

Andrew D. Ketsdever ◽

Michael T. Clabough ◽

Sergey F. Gimelshein ◽

Alina Alexeenko

Keyword(s):

Reynolds Numbers ◽

Numerical Determination ◽

Low Reynolds Numbers ◽

Low Reynolds

Download Full-text

Development of HPLC Method for the Purity Test by Design of Experiments and Determination of Activation Energy of Hydrolytic Degradation Reactions of Sofosbuvir

Current Pharmaceutical Analysis ◽

10.2174/1573412915666190225161007 ◽

2020 ◽

Vol 16 (7) ◽

pp. 976-987

Author(s):

Jakub Petřík ◽

Jakub Heřt ◽

Pavel Řezanka ◽

Filip Vymyslický ◽

Michal Douša

Keyword(s):

Activation Energy ◽

Design Of Experiments ◽

Mobile Phase ◽

Hydrolytic Degradation ◽

Isoconversional Method ◽

Hplc Method ◽

Organic Modifier ◽

Calculation Methods ◽

Degradation Reactions

Background: The present study was focused on the development of HPLC method for purity testing of sofosbuvir by the Design of Experiments and determination of the activation energy of hydrolytic degradation reactions of sofosbuvir using HPLC based on the kinetics of sofosbuvir degradation. Methods: Following four factors for the Design of Experiments were selected, stationary phase, an organic modifier of the mobile phase, column temperature and pH of the mobile phase. These factors were examined in two or three level experimental design using Modde 11.0 (Umetrics) software. The chromatographic parameters like resolution, USP tailing and discrimination factor were calculated and analysed by partial least squares. The chromatography was performed based on Design of Experiments results with the mobile phase containing ammonium phosphate buffer pH 2.5 and methanol as an organic modifier. Separation was achieved using gradient elution on XBridge BEH C8 at 50 °C and a flow rate of 0.8 mL/min. UV detection was performed at 220 nm. The activation energy of hydrolytic degradation reactions of sofosbuvir was evaluated using two different calculation methods. The first method is based on the slope of dependence of natural logarithm of the rate constant on inverted thermodynamic temperature and the second approach is the isoconversional method. Results and Conclusion: Calculated activation energies were 77.9 ± 1.1 kJ/mol for the first method and 79.5 ± 3.2 kJ/mol for the isoconversional method. The results can be considered to be identical, therefore both calculation methods are suitable for the determination of the activation energy of degradation reactions.

Download Full-text

Rational Choice of Reinforcement of Reinforced Concrete Frame Corners Subjected to Opening Bending Moment

Materials ◽

10.3390/ma14123438 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3438

Author(s):

Michał Szczecina ◽

Andrzej Winnicki

Keyword(s):

Cross Section ◽

Bending Moment ◽

Plasticity Model ◽

Reinforced Concrete Frame ◽

Moment Frame ◽

Concrete Frame ◽

Rational Reinforcement ◽

Eurocode 2 ◽

Analysis Of Results

This paper discusses a choice of the most rational reinforcement details for frame corners subjected to opening bending moment. Frame corners formed from elements of both the same and different cross section heights are considered. The case of corners formed of elements of different cross section is not considered in Eurocode 2 and is very rarely described in handbooks. Several reinforcement details with both the same and different cross section heights are presented. The authors introduce a new reinforcement detail for the different cross section heights. The considered details are comprised of the primary reinforcement in the form of straight bars and loops and the additional reinforcement in the form of diagonal bars or stirrups or a combination of both diagonal stirrups and bars. Two methods of static analysis, strut-and-tie method (S&T) and finite element method (FEM), are used in the research. FEM calculations are performed with Abaqus software using the Concrete Damaged Plasticity model (CDP) for concrete and the classical metal plasticity model for reinforcing steel. The crucial CDP parameters, relaxation time and dilatation angle, were calibrated in numerical tests in Abaqus. The analysis of results from the S&T and FE methods allowed for the determination of the most rational reinforcement details.

Download Full-text