Effect of Paraffin Oil Used as a Lubricant in Tensile Tests of Carbon Fibre Bundles

2006 ◽  
Vol 514-516 ◽  
pp. 672-676 ◽  
Author(s):  
Luís Guerra Rosa ◽  
Alberto Colella ◽  
Carlos A. Anjinho
Keyword(s):  
Global Change ◽  
Carbon Fibre ◽  
Liquid Paraffin ◽  
Tensile Tests ◽  
Displacement Curve ◽  
European Standard ◽  
Fibre Bundles ◽  
Liquid Lubricant ◽  
Paraffin Oil ◽  
Load Displacement

The failure of carbon fibre bundles of Tenax 5131 HTA with 6000 filaments is characterised using the European Standard EN 1007-5. It is shown that the addition of liquid paraffin to the bundle causes a global change of the load-displacement curve and the effects of the presence of a liquid lubricant are discussed.

Estimation of transverse tensile behavior of Zircaloy pressure tubes using ring-tensile test and finite element analysis

2012 ◽  
Vol 227 (6) ◽  
pp. 1177-1186 ◽  
Author(s):  
MK Samal ◽  
KS Balakrishnan ◽  
J Parashar ◽  
GP Tiwari ◽  
S Anantharaman
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Tensile Tests ◽  
Tensile Specimen ◽  
Displacement Curve ◽  
Stress Strain ◽  
Element Analysis ◽  
Transverse Tensile ◽  
Pressure Tubes ◽  
Load Displacement

Determination of transverse mechanical properties from the ring type of specimens directly machined from the nuclear reactor pressure tubes is not straightforward. It is due to the presence of combined membrane as well as bending stresses arising in the loaded condition because of the curvature of the specimen. These tubes are manufactured through a complicated process of pilgering and heat treatment and hence, the transverse properties need to be determined in the as-manufactured condition. It may not also be possible to machine small miniaturized specimen in the circumferential direction especially in the irradiated condition. In this work, we have performed ring-tensile tests on the un-irradiated ring tensile specimen using two split semi-cylindrical mandrels as the loading device. A three-dimensional finite element analysis was performed in order to determine the material true stress–strain curve by comparing experimental load–displacement data with those predicted by finite element analysis. In order to validate the methodology, miniaturized tensile specimens were machined from these tubes and tested. It was observed that the stress–strain data as obtained from ring tensile specimen could describe the load–displacement curve of the miniaturized flat tensile specimen very well. However, it was noted that the engineering stress–strain as directly obtained from the experimental load–displacement curves of the ring tensile tests were very different from that of the miniaturized specimen. This important aspect has been resolved in this work through the use of an innovative type of 3-piece loading mandrel.

Tensile Tests on High Strength Steel Q345 Notched Plates with the Moderate Thickness

2010 ◽  
Vol 143-144 ◽  
pp. 1450-1453
Author(s):  
Wan Zhen Wang ◽  
Lan Ying Jiang ◽  
Ren Quan Sun ◽  
Xin Tang Wang
Keyword(s):  
High Strength Steel ◽  
High Strength ◽  
Tensile Tests ◽  
Fracture Load ◽  
Displacement Curve ◽  
Notch Depth ◽  
Fracture Ductility ◽  
Notch Sharpness ◽  
Load Displacement ◽  
Notch Edge

In order to study fracture mechanics of high strength steel with the moderate thickness, fracture tests were performed on 10 elliptical notched plates with the thickness of 16mm fabricated from high strength steel Q345. The effect of notch sharpness (the ratio of the length of short axis to that of long axis of elliptic notch, b/a) and notch depth (the ratio of the length of long axis of elliptic notch to the width of plate, a/w) on fracture model of high strength steel was examined. Test results show that the first crack initiates at the notch edge. The fracture ductility is low for the specimens with the sharper notch (a smaller ratio b/a), and the point of crack load lies in hardening phase of load-displacement curve. The fracture ductility is high for the specimens with the obtuse notch (a bigger ratio b/a), and the point of fracture load lies in necking phase of load-displacement curve. There is no qualitative relationship of fracture ductility and the notch depth (a/w). The ultimate strength of notched plates is independent of the notch sharpness (b/a) and notch depth (a/w).

PULL-OUT PROPERTIES OF GYPSUM BOARD ANCHORS

2016 ◽  
Vol 3 (2) ◽  
Author(s):  
Yoshinori Kitsutaka ◽  
Fumiya Ikedo
Keyword(s):  
Numerical Model ◽  
Fracture Energy ◽  
Tensile Tests ◽  
Displacement Curve ◽  
Gypsum Board ◽  
Hydraulic Loading ◽  
Pull Out ◽  
Loading System ◽  
Earthquake Load ◽  
Load Displacement

In this study, pull-out properties of various anchors embedded in gypsum board were investigated. Tensile tests for anchors embedded in 200mm square size gypsum board were conducted to measure the load-load displacement curves. Strength of gypsum board was changed for three conditions and twelve kinds of anchors were selected which were ordinary used for gypsum board anchoring. The loading conditions were a monotonous loading and a repeating loading controlled by a servo-controlled hydraulic loading system to achieve accurate measurement. The fracture energy for each anchors were estimated by the analysis of consumed energy calculated by the load-load displacement curve. The effect of the strength of gypsum board and the types of anchors on the pull-out properties of gypsum board anchors was cleared. A numerical model to predict the load-unload curve of pull-out deformation of gypsum board anchors caused by such as the earthquake load was proposed and the validity on the model was proved.

Progressive damage characteristics of screwed single-lap CFRPI-metal joint subjected to tensile loading at RT and 350°C

2021 ◽  
pp. 002199832098559
Author(s):  
Yun-Tao Zhu ◽  
Jun-Jiang Xiong ◽  
Chu-Yang Luo ◽  
Yi-Sen Du
Keyword(s):  
Damage Model ◽  
Tensile Loading ◽  
Tensile Tests ◽  
Displacement Curve ◽  
Progressive Damage ◽  
Damage Characteristics ◽  
Metal Joint ◽  
Static Tensile ◽  
Strength And Stiffness ◽  
Progressive Damage Model

This paper outlines progressive damage characteristics of screwed single-lap CFRPI-metal joints subjected to tensile loading at RT (room temperature) and 350°C. Quasi-static tensile tests were performed on screwed single-lap CCF300/AC721-30CrMnSiA joint at RT and 350°C, and the load versus displacement curve, strength and stiffness of joint were gauged and discussed. With due consideration of thermal-mechanical interaction and complex failure mechanism, a modified progressive damage model (PDM) based on the mixed failure criterion was devised to simulate progressive damage characteristics of screwed single-lap CCF300/AC721-30CrMnSiA joint, and simulations correlate well with experiments. By using the PDM, the effects of geometry dimensions on mechanical characteristics of screwed single-lap CCF300/AC721-30CrMnSiA joint were analyzed and discussed.

scholarly journals Study on the Strength Performance of Recycled Aggregate Concrete with Different Ages under Direct Shearing

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2312
Author(s):  
Xin Liang ◽  
Fang Yan ◽  
Yuliang Chen ◽  
Huiqin Wu ◽  
Peihuan Ye ◽  
...  
Keyword(s):  
Shear Strength ◽  
Shear Force ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Displacement Curve ◽  
Direct Shear ◽  
Replacement Ratio ◽  
Aggregate Concrete ◽  
Concrete Failure ◽  
Load Displacement

In order to study the mechanical properties of recycled aggregate concrete (RAC) at different ages, 264 standard cubes were designed to test its direct shear strength and cube compressive strength while considering the parameters of age and recycled aggregate replacement ratio. The failure pattern and load–displacement curve of specimens at direct shearing were obtained; the direct shear strength and residual shear strength were extracted from the load–displacement curves. Experimental results indicate that the influence of the replacement ratio for the front and side cracks of RAC is insignificant, with the former being straight and the latter relatively convoluted. At the age of three days, the damaged interface between aggregate and mortar is almost completely responsible for concrete failure; in addition to the damage of coarse aggregates, aggregate failure is also an important factor in concrete failure at other ages. The load–displacement curve of RAC at direct shearing can be divided into elasticity, elastoplasticity, plasticity, and stabilization stages. The brittleness of concrete decreases with its age, which is reflected in the gradual shortening of the elastoplastic stage. At 28 days of age, the peak direct shear force increases with the replacement ratio, while the trend is opposite at ages of 3 days, 7 days, and 14 days, respectively. The residual strength of RAC decreases inversely to the replacement ratio, with the rate of decline growing over time. A two-parameter RAC direct shear strength calculation formula was established based on the analysis of age and replacement rate to peak shear force of RAC. The relationship between cube compressive strength and direct shear strength of recycled concrete at various ages was investigated.

A novel method to determine critical CTOA directly by load-displacement curve

2020 ◽  
Vol 230 ◽  
pp. 107013
Author(s):  
Ying Zhen ◽  
Xuyang Li ◽  
Yuguang Cao ◽  
Shihua Zhang
Keyword(s):  
Displacement Curve ◽  
Novel Method ◽  
Load Displacement

Research on the Relationship between Indenter Tip Radius and Hardness with a Self-Designed Nanohardness Test Device

2008 ◽  
Vol 392-394 ◽  
pp. 267-270
Author(s):  
Qiang Liu ◽  
Ying Xue Yao ◽  
L. Zhou
Keyword(s):  
Single Crystal ◽  
Indentation Depth ◽  
Single Crystal Silicon ◽  
Indentation Hardness ◽  
Displacement Curve ◽  
Test Device ◽  
Crystal Silicon ◽  
Load Displacement ◽  
Depth Sensitivity ◽  
Tip Radius

Nanoindentation device has the ability to make the load-displacement measurement with sub-nanometer indentation depth sensitivity, and the nanohardness of the material can be achieved by the load-displacement curve. Aiming at the influence law of indenter tip radius to indentation hardness, testing on the hardness of single-crystal silicon were carried out with the new self-designed nanohardness test device based on nanoindentation technique. Two kinds of Berkovich indenter with radius 40nm and 60nm separately were used in this experiment. According to the load-depth curve, the hardness of single-crystal silicon was achieved by Oliver-Pharr method. Experimental results are presented which show that indenter tip radius do influence the hardness, the hardness value increases and the indentation size effect (ISE) becomes obvious with the increasing of tip radius under same indentation depth.

Evaluation on Combustion Properties of Nanoparticle as Fuel Additive

2011 ◽  
Vol 335-336 ◽  
pp. 1516-1519 ◽  
Author(s):  
Yong Qiang Ren ◽  
Zhi Ning Huang ◽  
Yan Fu
Keyword(s):  
Liquid Paraffin ◽  
Fuel Additive ◽  
Average Particle ◽  
X Ray ◽  
Paraffin Oil ◽  
Transmission Electron ◽  
Combustion Properties ◽  
Fuel Oils ◽  
Save Energy ◽  
Similar Crystal Structure

To improve combustion properties of fuel oils, save energy and reduce pollution, the metal nanoparticles modified by fatty acids have been prepared. The dispersion capacities of these modified nanoparticles in liquid paraffin oil were examined, and were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectrum (FTIR) . The results show they possess similar crystal structure as organic shell, and average particle diameters, which are in agreement with their excellent oil-solubilities. Moreover, the properties of the modified nanoparticles additives in boiler fuel were evaluated by means of oxygen bomb relative method as regards energy saving and residual products lowering. The results show that the efficiency of combustion and decrement of residual products for fuels were improved to different degree. Therefore, notable economic and social benefits are brought.

scholarly journals Analysis of Bearing Strength of Post-Tensioning Anchorage Zone with Respect to Relative Bearing Area and Lateral Confinement Design

2021 ◽  
Vol 11 (18) ◽  
pp. 8386
Author(s):  
Jin-Kook Kim ◽  
Jun-Mo Yang
Keyword(s):  
Error Rate ◽  
Small Diameter ◽  
Average Error ◽  
Displacement Curve ◽  
Proportional Limit ◽  
Lateral Confinement ◽  
Bearing Strength ◽  
Bearing Plate ◽  
Load Displacement ◽  
Post Tensioning

This study aimed to evaluate the bearing strength of the post-tensioning anchorage zone with respect to the relative bearing area and lateral confinement design of spiral and stirrup rebars. Eleven specimens were fabricated and tested to fracture in accordance with EAD 160004-00-0301. Load-displacement curves and fracture modes were analyzed. Then, the conventional design equation for the bearing strength and previous findings on the relative bearing area was re-investigated in comparison with the test results. From the test, the representative findings are as follows: (1) A specimen with relatively small size and less lateral reinforcement is more likely to be affected by the wedge action of the anchorage device; however, a larger specimen is affected by both concrete crushing and/or spalling; (2) The behavior of the anchorage zone is markedly affected by the local behavior near the anchorage bearing plate, and the sectional efficiency is mostly determined by A/Ag; (3) For specimens with A/Ag = 9.52, the proportional limit of the load-displacement curve is determined by the yield of spiral rebar or fracture of the bearing plate, but the later part of the curve is determined by lateral confinement; (4) The maximum A/Ag that could produce 100% sectional efficiency is about 2.0 for the anchorage bearing plate used in the test; (5) For a fully confined specimen with a small-diameter spiral for minimum anchorage spacing, the stirrup rebar design mainly influences crack occurrence and patterns when the size of the specimen is equal to the minimum anchorage spacing; however, the area of the load-displacement curve after the proportional limit as well as crack occurrence and patterns are also influenced by stirrup rebar design when A/Ag is relatively large; (6) Finally, a revised design model is proposed to effectively estimate the ultimate bearing strength of the post-tensioning anchorage zone without respect to A/Ag. From the comparison of the design equations, it was concluded that the proposed equation provides a more reliable prediction with a 14.0% average error rate and 5.7% standard deviation of error rate.

scholarly journals Incidence of mercerization treatment in the mechanical properties of bamboo fibre bundles "Guadua Angustifolia Kunth" from colombian origin

DYNA ◽  
2019 ◽  
Vol 86 (210) ◽  
pp. 156-163 ◽  
Author(s):  
Leidy Johana Quintero Giraldo ◽  
Luis Javier Cruz ◽  
Jaime Alexis García ◽  
Alejandro Alcaraz ◽  
Eugenia González ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Tensile Tests ◽  
Good Correspondence ◽  
Fibre Bundles ◽  
Bamboo Fibre ◽  
Untreated Fibre ◽  
Mercerization Treatment ◽  
Mechanical Extraction

In this article, bamboo fibre bundles of "Guadua Angustifolia Kunth" specie were isolated from different locations of the basa zone: upper, middle and lower, through mechanical extraction method. The elastic modulus and the tensile strength were obtained with preliminary tensile tests. Applying the statistical analysis known as ANOVA, it was determined that the mechanical properties are similar in all the extension of the basa zone. From there, fibre bundles were extracted randomly, and a part of the fibre bundles was treated with NaOH (mercerization). Later, tensile tests with different calibration lengths were made for calculate the elastic modulus and the tensile strength of the treated and untreated fibre bundles. Best results belonged to the treated fibre bundles. A good correspondence between the results obtained in this work and the results reported in the literature was concluded. 

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