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.

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).

Investigation of the Tensile Fracture Behavior of Notched C/SiC Composite Using In Situ SEM and Micro-CT

2019 ◽  
Vol 298 ◽  
pp. 155-160
Author(s):  
Bai Hong Jiang ◽  
Yi Yu ◽  
Lei Zhang ◽  
Shi Zhang Yu ◽  
Xiao Jin Gao
Keyword(s):  
Failure Mechanism ◽  
Linear Part ◽  
Tensile Fracture ◽  
In Situ Observation ◽  
Displacement Curve ◽  
Micro Ct ◽  
Pull Out ◽  
Load Displacement ◽  
Sic Composites

In order to better understand the failure mechanism of C/SiC composites, the tensile behavior of notched C/SiC composites was investigated by the in-situ scanning electron microscopy (SEM) and the micro-CT technique. Surface morphologies of the C/SiC sample during tensile loading were in-situ observed by SEM, while the three-dimensional microscopic images of the C/SiC sample before loading and after failure were obtained by micro-CT. The results showed that no cracks formed in the initial elastic stage corresponding to the linear part of the load-displacement curve. However, corresponding to the following non-linear part of the load-displacement curve, matrix crack initiation, fiber pull-out, crack propagation and deflection appeared consecutively in the notched region of the sample. What’s more, different crack growth paths existed in different directions of the sample during tensile failure. In general, approximately flat fracture formed in the plying direction and serrated or stepped fracture were observed in the needling direction. It indicated that the in-situ observation method combining SEM and micro-CT can obtain the micro-structure images of the material in different states, which is helpful to analyze the fracture failure mechanism of composites.

Fracture Toughness Measurement of Asphalt Concrete by Nanoindentation

2017 ◽  
Author(s):  
Zafrul Khan ◽  
Hasan M. Faisal ◽  
Rafiqul Tarefder
Keyword(s):  
Fracture Toughness ◽  
Energy Release Rate ◽  
Fracture Energy ◽  
Energy Release ◽  
Release Rate ◽  
Asphalt Concrete ◽  
Nanoindentation Test ◽  
Displacement Curve ◽  
Macro Scale ◽  
Load Displacement

Fracture toughness and fracture energy release rate are two important parameters to understand the crack propagation within any material. Fracture toughness of asphalt concrete (AC) is vital to explain the fatigue cracking and low temperature cracking of asphalt pavement. These two types of distresses are still unsolved issues for asphalt researchers. Measuring fracture toughness of AC is not a new phenomenon. Recently, researchers have used several techniques to measure the fracture toughness of AC. Tests like semi-circular bending (SCB) and disk-shaped compact specimen (DCT) testing have been used to measure the fracture toughness of the AC. From the SCB or DCT tests, past researchers have shown that crack in AC propagates through mainly binder and mastic phase. All these conventional tests are carried out in macro scale. It is important to understand that before propagation of these macro scale cracks, the cracks initiates at the nano/micro scale level. With the increment of the loads these nanoscale cracks become macro scale cracks and propagates through the sample. Therefore, it is important to understand the cracks at nanoscale. In this study, nanoindentation test was introduced to measure the fracture toughness of the asphalt concrete. In a nanoindentation test, the sample surface is indented with a loaded indenter. For this test, Berkovich indenter with load control method was used. A field cored asphalt concrete sample was used for this study. The sample was collected by coring at interstate 40 (I-40) near Albuquerque, New Mexico. The sample was field aged for four years. The maximum load applied in this study was 5-mn and the unloading was done at a faster rate than the loading rate. From the load-displacement curves of the nanoindentation tests, fracture toughness of the samples was measured. The unloading curve of the nanoindentation test was further used to obtain reduced modulus of the asphalt concrete using Oliver-Pharr method. In this study, fracture energy is thought of as a portion of irreversible energy. This irreversible energy is comprised of plastic energy and energy required for propagation of crack. By analyzing the load displacement curve along with the maximum indentation depth, energy release rate and mode I fracture toughness of asphalt concrete was measured.

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.

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

Fiber Debonding Along a Crack Front in Paper

1998 ◽  
Vol 539 ◽  
Author(s):  
H. Kettunen ◽  
K. J. Niskanen
Keyword(s):  
Fracture Energy ◽  
Crack Front ◽  
Fracture Process ◽  
Fracture Process Zone ◽  
Process Zone ◽  
Bond Properties ◽  
Crack Line ◽  
Pull Out ◽  
Microscopic Damage ◽  
Debonding Process

AbstractWe follow the accumulation of microscopic damage ahead the crack tip in paper. The fiber debonding process varies even within each specimen because of large variation in fiber and bond properties. In general, stiff and weakly bonded fibers tend to debond as a rigid body while ductile or well bonded fibers pull out gradually in a process that propagates from the crack line to the fiber ends. Particularly in the latter case the network ruptures coherently rather than through debonding of single fibers. Experimental analysis and simulations show that fracture energy correlates closely with the size of the fracture process zone (FPZ) irrespective the nature of the debonding process. Only the cases of low bonding and stiff fibers seem to make an exception in that FPZ can grow in size without a corresponding increase in fracture energy.

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.

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