Experimental testing of the applicability of a fourth degree polynomial in describing surfaces of equicritical planar stress distributions in glass-reinforced plastics

1973 ◽  
Vol 6 (2) ◽  
pp. 251-258 ◽  
Author(s):  
E. K. Ashkenazi ◽  
F. P. Pekker
Keyword(s):  
Experimental Testing ◽  
Stress Distributions ◽  
Degree Polynomial ◽  
Fourth Degree ◽  
Reinforced Plastics

scholarly journals Simulation Tests of a Cow Milking Machine—Analysis of Design Parameters

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1358
Author(s):  
Ewa Golisz ◽  
Adam Kupczyk ◽  
Maria Majkowska ◽  
Jędrzej Trajer
Keyword(s):  
Mathematical Model ◽  
Simplified Model ◽  
Design Parameters ◽  
Degree Polynomial ◽  
Fourth Degree ◽  
Local Loss ◽  
Linear Drag ◽  
Milking Machine ◽  
Machine Analysis ◽  
The Impact

The objective of this paper was to create a mathematical model of vacuum drops in a form that enables the testing of the impact of design parameters of a milking cluster on the values of vacuum drops in the claw. Simulation tests of the milking cluster were conducted, with the use of a simplified model of vacuum drops in the form of a fourth-degree polynomial. Sensitivity analysis and a simulation of a model with a simplified structure of vacuum drops in the claw were carried out. As a result, the impact of the milking machine’s design parameters on the milking process could be analysed. The results showed that a change in the local loss and linear drag coefficient in the long milk duct will have a lower impact on vacuum drops if a smaller flux of inlet air, a higher head of the air/liquid mix, and a higher diameter of the long milk tube are used.

BENDING OF ORTHOTROPIC RECTANGULAR CANTILEVER PLATE

2021 ◽  
pp. 2-9
Author(s):  
M.V. Sukhoterin ◽  
◽  
A.M. Maslennikov ◽  
T.P. Knysh ◽  
I.V. Voytko ◽  
...  
Keyword(s):  
Iterative Method ◽  
Boundary Conditions ◽  
Trigonometric Series ◽  
Bending Moment ◽  
Partial Solution ◽  
Numerical Results ◽  
Cantilever Plate ◽  
Degree Polynomial ◽  
Fourth Degree ◽  
Beam Function

Abstract. An iterative method of superposition of correcting functions is proposed. The partial solution of the main differential bending equation is represented by a fourth-degree polynomial (the beam function), which gives a residual only with respect to the bending moment on parallel free faces. This discrepancy and the subsequent ones are mutually compensated by two types of correcting functions-hyperbolic-trigonometric series with indeterminate coefficients. Each function satisfies only a part of the boundary conditions. The solution of the problem is achieved by an infinite superposition of correcting functions. For the process to converge, all residuals must tend to zero. When the specified accuracy is reached, the process stops. Numerical results of the calculation of a square ribbed plate are presented.

Numerical and Experimental Analysis of the Thermo-Mechanical Load on Turbine Wheels of Turbochargers

2006 ◽  
Author(s):  
Tom Heuer ◽  
Bertold Engels ◽  
Achim Klein ◽  
Horst Heger
Keyword(s):  
Thermal Stresses ◽  
Mechanical Load ◽  
Experimental Testing ◽  
Transient Temperature ◽  
Heating Process ◽  
Stress Distributions ◽  
Validation Data ◽  
Turbine Wheel ◽  
Turbo Charger ◽  
Design Deficiencies

CFD, FEA, and experimental testing have been combined in order to investigate the lifetime limiting design deficiencies of a turbine wheel in a turbo charger. Thermocouples have been applied to the same radial turbine wheel to provide boundary conditions and validation data for the simulations. The tests have been performed on a turbocharger gas-stand. Based on two steady state CHT-calculations for two distinctly different operating points the heating process of the wheel has been simulated in a transient temperature calculation. Since the resulting temperature gradients induce thermal stresses, the temperature distribution serves as a boundary condition for the subsequent structural analysis. To obtain realistic stress distributions, centrifugal forces also need to be accounted for. In this way, the influence of the thermal stress on the overall stress can be evaluated.

Complete Solution to the Eight-Point Path Generation of Slider-Crank Four-Bar Linkages

2010 ◽  
Vol 132 (8) ◽  
Author(s):  
Hafez Tari ◽  
Hai-Jun Su
Keyword(s):  
Complete Solution ◽  
Solution Process ◽  
Polynomial Equations ◽  
Homotopy Methods ◽  
Degree Polynomial ◽  
Fourth Degree ◽  
Augmented System ◽  
Polynomial Curve ◽  
Four Bar Linkage ◽  
Classical Homotopy

We study the synthesis of a slider-crank four-bar linkage whose coupler point traces a set of predefined task points. We report that there are at most 558 slider-crank four-bars in cognate pairs passing through any eight specified task points. The problem is formulated for up to eight precision points in polynomial equations. Classical elimination methods are used to reduce the formulation to a system of seven sixth-degree polynomials. A constrained homotopy technique is employed to eliminate degenerate solutions, mapping them to solutions at infinity of the augmented system, which avoids tedious post-processing. To obtain solutions to the augmented system, we propose a process based on the classical homotopy and secant homotopy methods. Two numerical examples are provided to verify the formulation and solution process. In the second example, we obtain six slider-crank linkages without a branch or an order defect, a result partially attributed to choosing design points on a fourth-degree polynomial curve.

Contact Stress Analysis Around Elliptic Pin-Loaded Holes in Orthotropic Plates

2010 ◽  
Author(s):  
O. Aluko ◽  
H. A. Whitworth
Keyword(s):  
Coulomb Friction ◽  
Complex Stress ◽  
Stress Distributions ◽  
Orthotropic Plates ◽  
Carbon Fiber Reinforced Plastics ◽  
Reinforced Plastics ◽  
Method Of Solution ◽  
Stress Functions ◽  
Fiber Reinforced Plastics ◽  
Lower Magnitude

This analysis utilizes the complex stress function approach to obtain the stress distribution in pin loaded composite joints with elliptic openings. The stress functions were derived from assumed displacement expressions that satisfy the boundary conditions around the hole. In the method of solution Coulomb friction was used to determine the prescribed displacements at the boundary. The material properties of graphite/epoxy and carbon fiber reinforced plastics laminates were used in this investigation and the results also compared with available data for joints with circular openings. It was revealed that the stress distributions followed the same pattern in both geometries but with lower magnitude in elliptical shape and the reduction in stress distributions caused by changing the pin/hole shape from circular to elliptic depend on friction.

Integrability of Hamiltonians with third‐ and fourth‐degree polynomial potentials

1983 ◽  
Vol 24 (9) ◽  
pp. 2289-2295 ◽  
Author(s):  
B. Grammaticos ◽  
B. Dorizzi ◽  
A. Ramani
Keyword(s):  
Degree Polynomial ◽  
Fourth Degree ◽  
Polynomial Potentials

scholarly journals Distribution of Trichinella infections in pigs and Trichinellosis in humans in Serbia from 1994 to 2018

2019 ◽  
Vol 73 (2) ◽  
pp. 133-143 ◽  
Author(s):  
Milorad Mirilovic ◽  
Nada Tajdic ◽  
Branislav Vejnovic ◽  
Spomenka Djuric ◽  
Nikola Mirilovic ◽  
...  
Keyword(s):  
Polynomial Function ◽  
Winter Season ◽  
Degree Polynomial ◽  
Surveillance Period ◽  
Mammal Species ◽  
Fourth Degree ◽  
Trend Line ◽  
Trichinella Infection ◽  
The World ◽  
The Republic

Introduction. Trichinellosis is a disease in humans caused by parasites of the genus Trichinella, and these roundworms can occur in a variety of animals (over one hundred mammal species). Members of the genus Trichinella are present in almost all continents and in all climate zones. Intensive studies on the eradication of this disease have been going on for a long period, but despite the finances invested in research projects, trichinellosis is still present in the 21st century and poses a major health issue all over the world. According to current scientific estimations, there are over 27 million Trichinellainfected people in the world. The aim of our study was to determine the distribution and trends for Trichinella infection in pigs and trichinellosis in humans in Serbia between 1994 and 2018. Materials and Methods. Data for the 25-year surveillance period of Trichinella cases registered in pigs and humans in Serbia was gathered from the Veterinary Directorate and from the Institute of Public Health of the Republic of Serbia. The data obtained was analysed with the relative numbers of structure and dynamics, indices and descriptive statistical indicators. Results and Conclusions. During the research period, 14,837 pigs were diagnosed as infected with Trichinella. Out of this number, 87.31% of pigs were identified in the five epizootiological regions, and only 12.69% were diagnosed in the non-epizootiological regions in Serbia. During the period 1994-2018 in Serbia, a total of 6,850 people were treated for Trichinella infection. Out of this number, 4,153 (60.63%) people were from the five epizootiological regions. The trend-line describing the presence of Trichinella in pigs was defined by a fourth degree polynomial function. Meanwhile, the trend-line describing the presence of trichinellosis in humans was defined by a sixth degree polynomial function. Trichinellosis in Serbia is most common during the winter season, from December to March.

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