scholarly journals Prompt Determination of the Mechanical Properties of Industrial Polypropylene Sandwich Pipes

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2128
Author(s):  
Sergejs Vidinejevs ◽  
Rafal Chatys ◽  
Andrey Aniskevich ◽  
Krzysztof Jamroziak
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Relative Position ◽  
Foam Core ◽  
Linear Elastic ◽  
Sewer Network ◽  
Finite Element Calculations ◽  
Elastic Approximation ◽  
Gravity Sewer

A simple and prompt method to determine the mechanical properties of industrial multilayer extrusion polypropylene pipes for a gravity sewer network is suggested. The engineering formulas included for calculating the permissible thickness and relative position of a foam core in the pipes are based on a linear-elastic approximation and the rule of mixtures. The applicability of the approximation was justified experimentally during investigation of the effective tensile characteristics of single- and multilayer pipes and each layer specimen by using traditional tests and finite-element calculations. The results obtained were used to formulate engineering recommendations for calculations of this type.

Analytical and 3D Finite Element Study of the Deflection of an Elastic Cantilever Bilayer Plate

2010 ◽  
Vol 78 (1) ◽  
Author(s):  
M. Chekchaki ◽  
V. Lazarus ◽  
J. Frelat
Keyword(s):  
Thin Films ◽  
Finite Element ◽  
Three Dimensional ◽  
Analytical Formula ◽  
Mechanical Stresses ◽  
Linear Elastic ◽  
Wide Range ◽  
Finite Element Calculations ◽  
Analytical Formulas ◽  
Three Dimensional Elasticity

The mechanical system considered is a bilayer cantilever plate. The substrate and the film are linear elastic. The film is subjected to isotropic uniform prestresses due for instance to volume variation associated with cooling, heating, or drying. This loading yields deflection of the plate. We recall Stoney’s analytical formula linking the total mechanical stresses to this deflection. We also derive a relationship between the prestresses and the deflection. We relax Stoney’s assumption of very thin films. The analytical formulas are derived by assuming that the stress and curvature states are uniform and biaxial. To quantify the validity of these assumptions, finite element calculations of the three-dimensional elasticity problem are performed for a wide range of plate geometries, Young’s and Poisson’s moduli. One purpose is to help any user of the formulas to estimate their accuracy. In particular, we show that for very thin films, both formulas written either on the total mechanical stresses or on the prestresses, are equivalent and accurate. The error associated with the misfit between our theorical study and numerical results are also presented. For thicker films, the observed deflection is satisfactorily reproduced by the expression involving the prestresses and not the total mechanical stresses.

Determination of C2 Stress Index of Back-to-Back Welded Piping Bends Using Finite Element Method

2006 ◽  
Author(s):  
Dan Vlaicu ◽  
Manohar Lal Aggarwal ◽  
Ming Li
Keyword(s):  
Finite Element ◽  
Central Line ◽  
Stress Index ◽  
Element Analysis ◽  
Butt Weld ◽  
Linear Elastic ◽  
Out Of Plane ◽  
Parametric Studies ◽  
Welded Pipe

In current ASME Boiler and Pressure Vessel Code, the C2 stress index for back-to-back elbows welded together is taken as the product of the C2 index of the elbow and the C2 index of the girth butt weld. In recent years, many finite element analyses studies have been conducted on the elbow C2 index itself which have found that the code C2 value is conservative. The girth butt weld C2 given in the code resulted from analytical studies on transition joint between two straight pipes. While the code considers that the secondary stress due to the weld reinforcement including the effect from the mismatch to be small and practically negligible for a thick pipe, it recommends a formula to calculate C2 for weld in a thin pipe of thickness less than 0.237”. The purpose of this paper is to present an approach that C2 caused by weld mismatch can be determined by finite element analysis. Back-to-back bends are modeled with 2 typical configurations: in-plane and out-of-plane. Parametric studies of linear elastic secondary stresses are carried out to determine the “worst possible” two bend central line mismatch. The stress indices at elbows and weld location are established. It is found that the C2 index based on the code formula is overly conservative for back-to-back welded pipe bends and the multiplication by the C2 index of the weld is not needed.

Computational mechanical property determination of viscoelastic/plastic materials from nanoindentation creep test data

2009 ◽  
Vol 24 (3) ◽  
pp. 1245-1257 ◽  
Author(s):  
Jianjun Wang ◽  
Timothy C. Ovaert
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Finite Element ◽  
Test Data ◽  
Plastic Material ◽  
Test Method ◽  
Element Formulation ◽  
Unknown Parameters ◽  
Plastic Materials

Nanoindentation is a widely accepted test method for materials characterization. On account of the complexity of contact deformation behavior, design of parametric constitutive models and determination of the unknown parameters is challenging. To address the need for identification of mechanical properties of viscoelastic/plastic materials from nanoindentation data, a combined numerical finite element/optimization-based indentation modeling tool was developed, fully self-contained, and capable of running on a PC as a stand-alone executable program. The approach uses inverse engineering and formulates the material characterization task as an optimization problem. The model development consists of finite element formulation, viscoelastic/plastic material models, heuristic estimation to obtain initial solution boundaries, and a gradient-based optimization algorithm for fast convergence to extract mechanical properties from the test data. A four-parameter viscoelastic/plastic model is presented, then a simplified three-parameter model with more rapid convergence. The end result is a versatile tool for indentation simulation and mechanical property analysis.

Experimental Determination of Mechanical Properties for the Purposes of Numerical Simulations of Car Bumper Tests

2015 ◽  
Vol 732 ◽  
pp. 59-62
Author(s):  
Petr Horník
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Numerical Simulations ◽  
Experimental Determination ◽  
Input Data ◽  
Fe Analysis ◽  
Experimental Methodology ◽  
Material Input

Finite-element (FE) analysis is important instrument for prediction of plastic car bumper tests. Accuracy of FE analysis depends on accuracy of material input data. It has developed experimental methodology for identification of mechanical properties. The methodology leads to more accurate material input data for numerical simulations.

Micromechanical Characterization of Gasb by Microbeam Deflecion and Using Nanoprobe and Finite Element Analysis

2003 ◽  
Vol 782 ◽  
Author(s):  
M. Ospina ◽  
S. R. Vangala ◽  
D. Yang ◽  
J. A. Sherwood ◽  
C. Sung ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Young’S Modulus ◽  
Gallium Antimonide ◽  
Young's Modulus ◽  
Elastic Behavior ◽  
Material System ◽  
Scaling Effects ◽  
Commercial Development ◽  
Linear Elastic

ABSTRACTThe commercial development of low-power electronics and electro-optics based on antimonides demands a better understanding of the mechanical properties of ternary and quaternary thin-film alloys fabricated from the InGaAlAsSbP material system. Of particular importance is the determination of Young's modulus of these materials. In this paper, a technique for studying the mechanical behavior of these thin films was developed by using microbeam bending and finite element modeling. The technique was successfully applied to investigate the mechanical properties of GaSb. A test structure consisting of an array of gallium antimonide microbeams was fabricated with lengths ranging from 50 to 500 μm long. The microbeams were deflected using a calibrated nanoprobe, thereby generating load-displacement curves. Young's modulus was then extracted from the data using beam bending theory and a finite element simulation of the structures under load. A total of five microbeams with the same trapezoidal cross-section and lengths of 80, 85, 200, 250 and 500 μm were tested to study the technique applicability and size scaling effects on the mechanical properties. It was observed that the 80 and 85 μm beams exhibited linear elastic behavior and the 200, 250, and 500 μm microbeams exhibited non-linear elastic behavior.

Determination of Natural Frequencies of Spherical Cells

2008 ◽  
Author(s):  
Marjan Molavi ◽  
Ali Bonakdar ◽  
Ion Stiharu
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Living Cells ◽  
Health Condition ◽  
Comprehensive Analysis ◽  
Yeast Cells ◽  
Spherical Cells

In this paper, a finite element (FE) and scaled-up experimental modal analysis are employed to estimate the natural frequencies of the baker’s yeast cells. It is apparent the mechanical properties of the living cells and particularly the natural frequencies are highly related to the health condition of cells, and therefore a comprehensive analysis is carried out to determine the natural frequencies of individual cells.

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