Non-local failure theory and two-parameter tensile strength model for semi-circular bending tests of granitic rocks

Author(s):  
Wei Yao ◽  
Kaiwen Xia ◽  
Xing Li
Symmetry ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1023
Author(s):  
Hari Mohan Srivastava ◽  
Sheza M. El-Deeb

In this paper, we investigate several fuzzy differential subordinations that are connected with the Borel distribution series Bλ,α,β(z) of the Mittag-Leffler type, which involves the two-parameter Mittag-Leffler function Eα,β(z). Using the above-mentioned operator Bλ,α,β, we also introduce and study a class Mλ,α,βFη of holomorphic and univalent functions in the open unit disk Δ. The Mittag-Leffler-type functions, which we have used in the present investigation, belong to the significantly wider family of the Fox-Wright function pΨq(z), whose p numerator parameters and q denominator parameters possess a kind of symmetry behavior in the sense that it remains invariant (or unchanged) when the order of the p numerator parameters or when the order of the q denominator parameters is arbitrarily changed. Here, in this article, we have used such special functions in our study of a general Borel-type probability distribution, which may be symmetric or asymmetric. As symmetry is generally present in most works involving fuzzy sets and fuzzy systems, our usages here of fuzzy subordinations and fuzzy membership functions potentially possess local or non-local symmetry features.


2015 ◽  
Vol 1114 ◽  
pp. 9-12
Author(s):  
Alexandru Ghiban ◽  
Brandusa Ghiban ◽  
Cristina Maria Borţun ◽  
Nicolae Serban ◽  
Mihai Buzatu

Four compositions of some usually commercial dental alloys were investigated in order to determine the mechanical characteristics and fractographic analysis of tensile and bending tests surfaces. A correlation between chemical composition (either molybdenum or molybdenum and chromium contents) and mechanical characteristics (longitudinal modulus, tensile strength and elongation) were finally done.


Author(s):  
L. A. Ryabicheva ◽  
R. E. Velikotskii

Meeting the high requirements to the whole complex of mechanical characteristics is the main criteria of reliability and long service life of shipbuilding steels. To determine them it is necessary to apply modern methodologies of metal science analysis. Revelation of regularity of influence of alloying, carbon equivalent, microstructure and production technology on results of bending test of low-alloyed grades А32, D32, Е32 shipbuilding steels was the purpose of the study. Production of steel, rolling, thermal treatment, mechanical tests and metal science studies of the low-alloyed shipbuilding steels was made in Alchevsk steel-works. A quantity estimation of the D32 grade sheets microstructure was made as a result of studies, having both satisfactory and not satisfactory results of bending tests. It was determined, that stitch oxides have the most negative influence on the results of bending tests for both hot-rolled and normalized sheets. Sheets with not satisfactory results of bending tests differ from those, which passed the tests by higher value of streakiness points, particular of perlite, and in normalized condition – by higher value of Widmanstatten pattern. Sheets, which did not passed the tests, have yield strength by 5–25 MPa and tensile strength by 14–39 MPa higher, while the tensile strength was by 1.2–4.8% lower. For stable yield in bending tests within 98–100% it is necessary the tensile strength level to be not less than 30%. It is reasonably all the sheets of 10–20 mm thick out of heats with carbon equivalent higher 0.54% to subject compulsory normalization. Further increase of the sheets product yield can be achieved by decreasing of phosphor mass share and increasing of general steel purity, first of all, by decreasing of oxide inclusions


2015 ◽  
Vol 52 (11) ◽  
pp. 1874-1885 ◽  
Author(s):  
Bibiana Narvaez ◽  
Michel Aubertin ◽  
Faustin Saleh-Mbemba

Bending tests were conducted on specimens of unsaturated tailings from three hard rock mines to evaluate their tensile strength. Saturated samples were prepared at an initial water content, w0, of 40% and then naturally dried under ambient conditions to pre-selected degrees of saturation, Sr, which can be related to the corresponding suction using the water retention curve. The basic interpretation of the bending tests results is based on an elastic–brittle behavior. The results show how the tensile strength, σt, of unsaturated tailings varies with water content, w (and Sr). The experimental data are also used to evaluate Young’s modulus in tension, Et, and to estimate the apparent cohesion, capp, as a function of Sr. Predictive equations are also applied to estimate the values of σt of unsaturated tailings using the water retention curve.


Metrika ◽  
2006 ◽  
Vol 65 (3) ◽  
pp. 261-273 ◽  
Author(s):  
K. Krishnamoorthy ◽  
Shubhabrata Mukherjee ◽  
Huizhen Guo
Keyword(s):  

2019 ◽  
Vol 292 ◽  
pp. 9-14 ◽  
Author(s):  
Oldrich Sucharda ◽  
Vlastimil Bilek

Concrete is typical composite material and its properties can be very variable. Material properties are also influenced with the technology of processing, manufacturing and treatment after concreting. Reinforcement in form of fibers is often added for improving tensile strength. This paper deals with specific testing of fibre concrete. Test results of series of specimens are presented for selected transport concrete composition, which is reinforced with amount of fibers 25, 50, 75 kg / m3. Fibers were added directly into the into the concrete mixer in the factory. Each series includes more than 25 test samples. The tests include the compressive strength of a cube and cylindrical, testing of modulus of elasticity, and the split tensile strength in the direction perpendicular to and parallel to the filling. Within the research project also a few types of bending tests were performed. Four variants of bending test that vary in span of 500 or 600 mm, samples with and without a notch, and in a three- / four-point configuration. As a summary, broader evaluation and functional dependencies are derived.


2010 ◽  
Vol 168-170 ◽  
pp. 1325-1329
Author(s):  
Ye Ran Zhu ◽  
Jun Cai ◽  
Dong Wang ◽  
Guo Hong Huang

This paper investigates the mechanical properties (compressive strength, splitting tensile strength and flexural toughness) of polypropylene fiber reinforced self-compacting concrete (PFRSCC). The effect of the incorporation of polypropylene fiber on the mechanical properties of PFRSCC is determined. Four point bending tests on beam specimens were performed to evaluate the flexural properties of PFRSCC. Test results indicate that flexural toughness and ductility are remarkably improved by the addition of polypropylene fiber.


Author(s):  
Cory Kendall ◽  
Greg R. Doud

This report investigates failure properties of a unidirectional fiber-reinforced E-glass epoxy resin matrix (CYCOM 5216). This material is used in military and commercial helicopter blades and structures and is commonly used in engine nacelles. Testing and failure analysis is critical for these structures, which undergo vibratory and complex aerodynamic loading. Defined manufacturing methods were modified to produce thick samples containing wrinkle defects. Wrinkles were added to simulate realistic marcelling, which commonly occurs within complex structures. All samples were validated using volume fraction experiments. Static uniaxial tension and five-point bending testing was performed as strain was measured using a multi-axis strain gage or an axial extensometer. Tensile and shear moduli, tensile strength, and shear strength were all determined. Shear modulus was determined through the use of a reinforced five point bending apparatus. The effects of fiber waviness on static strength were observed by testing samples with wrinkles of varying amplitude in both shear and tension. Fatigue analysis in this study differs from previous finite element crack growth studies due to the introduction of fiber waviness. For this reason, previous mixed mode bending tests and analytical methods were used with finite element techniques to improve failure prediction methods.


Author(s):  
Benjamin L. Levy-Wendt ◽  
Alaina M. Bever ◽  
Nicholaus C. Wright ◽  
Timothy J. Venable ◽  
John P. Dally ◽  
...  

Unidirectional carbon-fiber-reinforced polymer (CFRP) composites with interleaved carbon nanotube (CNT) sheets were manufactured using a heated press. The effect of CNT sheets on the interlaminar tensile strength (ILTS) of composite laminates was measured using curved beam bending tests. Two sets of [0]24 T800S/3900-2B specimen were prepared using carbon fiber prepregs and non-woven CNT sheets, with specimen thickness and radial geometries conforming to ASTM D6415. Epoxy resin loaded CNT sheets were inserted in the mid-radius region of curved beam specimens during the lay-up process. The measured interlaminar tensile strengths (ILTS) were compared between the CNT-enhanced and baseline CFRP specimens. Specimen fracture surfaces were examined with optical microscopy to determine the mode of failure and to confirm that fracture occurred at the location with the highest radial stresses. CNT sheet enhancements have shown to improve ILTS by 42%, with all failures initiating at the CNT interlayer and the polymer matrix interface.


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