Effect of Impactor Shape on Residual Tensile Strength and Tensile Failure of Carbon/Epoxy Laminates

1989 ◽  
pp. 323-331
Author(s):  
M. M. Stevanović ◽  
T. B. Stecenko ◽  
M. C. Kostić ◽  
D. B. Briški-Gudić
Keyword(s):  
Tensile Strength ◽  
Tensile Failure

scholarly journals EP.TU.659Comparison of Gallbladder Tissue Tensile Strength between Thiel Embalmed Cadavers and Living Patients

2021 ◽  
Vol 108 (Supplement_7) ◽  
Author(s):  
Deona Mei Lam Chan ◽  
Kostantinos Rossolatos ◽  
Stuart Brown ◽  
Afshin Alijani ◽  
Christoph Kulli
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Patient Group ◽  
Surgical Training ◽  
Tensile Failure ◽  
Tissue Properties ◽  
The Mean ◽  
Mean Strain ◽  
Anatomy Teaching ◽  
Mechanical Tissue

Abstract Aim Formalin-embalmed cadavers have traditionally been used as an integral part of anatomy teaching and surgical training. Cadaveric tissue can, however, be compromised by distorted appearance, shrinkage, rigidity and unnatural colouration. The Thiel embalming process produces more ‘life-like’ specimens and it could be postulated that these may be more suitable for surgical training. This study aimed to provide quantifiable and repeatable measurements for the mechanical tissue properties of Thiel embalmed cadavers. Methods Four gallbladders were removed from Thiel Embalmed cadavers and eleven from living patients during laparoscopic cholecystectomies. The specimens were prepared into a uniform ‘hour-glass’ shape. The cadaveric specimens were loaded onto the Instron tensometer and the patient specimens were loaded onto a portable hand-held tensometer. The samples were extended until complete tensile failure occurred allowing measurement of the tissues’ tensile strength and strain. Results Nine samples were obtained from the four Thiel embalmed gallbladders and 27 samples yielded from the 11 living patients’ gallbladders. The mean ultimate tensile strength of the Thiel samples was 2.16 ± 0.91 MPa compared with 2.24 ± 1.40 MPa in the living patient group (p = 0.85). The Thiel embalmed cadaveric samples had a lower measured mean strain than the living patient gallbladders of (123 ± 33% vs. 233 ± 91%, p < 0.01). Conclusion This study demonstrates that, while tissue strength is well preserved, there may be some differences in how the tissues feel, related to differences in elongation during handling in Thiel embalmed gallbladder tissue.

scholarly journals Experimental Study of Brazilian Tensile Strength of Concrete Under Static Loads

2020 ◽  
Vol 206 ◽  
pp. 01018
Author(s):  
Rui Li ◽  
Lei Liu ◽  
Zhihua Zhang ◽  
Huaming An
Keyword(s):  
Tensile Strength ◽  
Testing Machine ◽  
Damage Index ◽  
Modern Society ◽  
Strength Test ◽  
Test Method ◽  
Tensile Failure ◽  
Brazilian Tensile Strength ◽  
Failure Patterns ◽  
Tensile Strength Test

Concrete is one of the most significant materials in modern society. It is widely used in many projects. Thus it is essential to study the strength and the failure patterns of this material. As well known, the compressive strength is much higher than the tensile strength for concrete. Thus, it is easy to fail due to the tensile strength for concrete. Thus, this paper focuses on the study of the tensile strength of the concrete and its failure patterns. Three types of concretes are made for studying the tensile strengths and the failure patterns of the concretes. Then the Brazilian tensile strength test method is employed in this study. The mythology of calculating tensile strength by the Brazilian tensile strength test method is introduced. Many discs are made for the tests. The Rock mechanics testing machine is used to excavate pressure on the top and bottom of the disc. It is concluded that the failure of the disc is along the vertical diameter between the top and bottom plates contacting the dis. The tensile failure is not obviously influenced by the ratios of the materials while the tensile strength is significantly influenced by the ratios of the concrete. The damage index of concrete is also proposed to describe the capabilities of resisting failure.

scholarly journals Post corrosion tensile strength and failure of dissimilar friction stir welded aluminium alloys

2020 ◽  
Vol 326 ◽  
pp. 04008
Author(s):  
Madhav Raturi ◽  
Anirban Bhattacharya
Keyword(s):  
Tensile Strength ◽  
Aluminium Alloys ◽  
Base Material ◽  
Fracture Morphology ◽  
Stir Zone ◽  
Tensile Failure ◽  
Friction Stir ◽  
Corrosive Solution ◽  
Dissimilar Weld ◽  
Dissimilar Friction Stir Welding

The present study efforts towards appraising the effects of corrosion on the tensile and fracture behaviour of dissimilar friction stir welding (FSW) of aluminium alloys. Three different dissimilar FSW joints obtained between AA6061-T6 and AA7075-T651, AA6061-T6 and AA2014-T6, AA7075-T651 and AA2014-T6, using threaded pin profile with three flat faces (TIF) tool at rotational speed of 1200 rpm and welding speed of 98 mm/min. The maximum joint tensile strength was achieved for AA7075-AA2014 joints followed by AA6061-AA2014 and least recorded for AA6061-AA7075 for as obtained FSW joints (non-corroded). The joints are further immersed into a corrosive solution for 1, 2, 7 and 14 days duration. The corrosion occurred all over the joint but much accelerated rate of exfoliation corrosion exists away from stir zone near the confluence of heat affected zone and base material irrespective of the advancing or retreating side. With increase in corrosion time the location of tensile failure shifted towards corroded region (AA6061-T6) instead of stir zone in dissimilar weld joint AA6061-AA2014, whereas it remained unchanged for other two joints. The fractured surfaces of AA6061-AA2014 FSW joints reveals the articulated view of pits and fracture morphology advocating the loss in YS, UTS and % elongation with increases in immersion duration.

scholarly journals Numerical study on rupture process of fiber-reinforced composites

2018 ◽  
Vol 16 (1_suppl) ◽  
pp. 46-54
Author(s):  
Daguo Wang ◽  
Chaochao Han ◽  
Bing Xu ◽  
Bin Li
Keyword(s):  
Tensile Strength ◽  
Numerical Study ◽  
Element Model ◽  
Fiber Composites ◽  
Composite Fiber ◽  
Single Fiber ◽  
Tensile Failure ◽  
Uniaxial Tensile ◽  
Total Width ◽  
Uniaxial Tensile Stress

Introduction: This study aims to investigate the strength characteristics of fiber composites under uniaxial tensile stress. Methods: A tensile failure finite element model based on fracture mechanics was built for fiber composites. The principal stress concentration–release–transfer evolution and the crack propagation of the composites under the conditions of equal single fiber width, unequal quantity, and equal total fiber width and unequal quantity were discussed. Results: The tensile strength of the composites increased with fiber quantity when the width of each single fiber was equal. Conclusions: The tensile strength of the composites increased with fiber quantity when the total width of the composite fiber was equal.

scholarly journals Investigating and Optimizing the Process Variables Related to the Tensile Properties of Short Jute Fiber Reinforced with Polypropylene Composite Board

2012 ◽  
Vol 7 (4) ◽  
pp. 155892501200700 ◽  
Author(s):  
Saravanan Kannappan ◽  
Bhaarathi Dhurai
Keyword(s):  
Tensile Strength ◽  
Tensile Properties ◽  
Fiber Composite ◽  
Tensile Tests ◽  
Tensile Failure ◽  
Jute Fiber ◽  
Effect Of Temperature ◽  
Composite Board ◽  
Predicted Values ◽  
Experimental Pressure

The effect of temperature, pressure, and time on the tensile strength of jute fiber composite has been studied. The process of preparing the composite specimens is discussed. The best tensile properties were observed if the composite board is manufactured using high pressure and moderate temperature. For tensile strength, the time does not play a significant role. The study identifies the principal experimental pressure variables, which have the greatest effect on the tensile strength of the composite. The composite boards were subjected to tensile tests and the fractured surfaces were observed under SEM. The SEM photomicrographs of the fractured surfaces of the composite board show diverse extents of fiber pull-outs under tensile failure. The tensile strength values are in good concurrence with predicted values and were found have a correlation coefficient of 96%.

Effects of Randomness of Material Parameters on Crack Failure of Concrete

2006 ◽  
Vol 324-325 ◽  
pp. 243-246
Author(s):  
Cheng Bin Du ◽  
Chao Jun Ren ◽  
Zong Quan Ying
Keyword(s):  
Tensile Strength ◽  
Strain Localization ◽  
Ultimate Load ◽  
Damage Model ◽  
Random Parameter ◽  
Tensile Failure ◽  
Material Parameters ◽  
Brittle Behavior ◽  
Three Phase ◽  
Random Aggregate

Concrete is taken as three-phase composites consisting of aggregate, interface and mortar matrix in the paper. The tensile strength and elastic modulus of each phase material are assumed to obey Weibull distribution. A few random aggregate and random parameter models are generated by Monte-Carlo method. Tensile failure of micro element is described by tension damage model, in which the stress will be reduced linearly after the stress reaches the maximum tensile strength. The results show that more cracks of lower homogenous specimens are observed than those of higher homogenous specimens. The phenomenon of discontinuous cracking is observed in the former, while strain localization and brittle behavior is observed in the latter. The ultimate load obtained in the numerical simulation agrees well with that of the test.

Mesoscopic finite element analysis on dynamic direct tensile failure of lightweight aggregate concrete and corresponding size effect

2021 ◽  
pp. 105678952110441
Author(s):  
Wenxuan Yu ◽  
Liu Jin ◽  
Xi Liu ◽  
Xiuli Du
Keyword(s):  
Tensile Strength ◽  
Size Effect ◽  
Strain Rate ◽  
Lightweight Aggregate ◽  
Tensile Failure ◽  
Lightweight Aggregate Concrete ◽  
Element Analysis ◽  
Aggregate Concrete ◽  
Direct Tensile ◽  
Direct Tensile Strength

A comprehensive finite element analysis at the mesoscopic level has been conducted into the complex topic of size effect coupling dynamic strain-rates. Taking the lightweight aggregate concrete (LWAC) dumbbell-shaped samples as the object of numerical investigation, the influence of strain-rate (with the range of 10−5/s ∼ 100/s) on direct-tensile failure of LWAC (including different lightweight aggregate volume fractions [Formula: see text] = 40%, 30% and 20%) was discussed. Subsequently, the structure size of LWAC samples was further expanded (width W = 100, 200 and 300 mm) and the dynamic size effect on direct-tensile strength was investigated. Numerical results show that both the direct-tensile strength and its corresponding size effect of LWAC exhibit a strain-rate dependent behaviour. The increasing strain-rate can gradually weaken the size effect of LWAC and direct-tensile strength would be independent to the structure size as the strain-rate reaches the critical strain-rate. The increasing lightweight aggregate volume fraction can reduce direct-tensile strength. Furthermore, a dynamic size effect model establishing the direct link between the strain-rate effect and size effect was proposed, which can quantitatively predict the dynamic direct-tensile strength of LWAC.

A New Approach to Determine Cutting Forces in Brittle Rock Under Hyperbaric Conditions

2014 ◽  
Author(s):  
Sape A. Miedema
Keyword(s):  
Tensile Strength ◽  
Shear Strength ◽  
Cutting Forces ◽  
Brittle Failure ◽  
Cutting Process ◽  
Tensile Failure ◽  
Atmospheric Conditions ◽  
New Approach ◽  
Ductile Cutting ◽  
Hyperbaric Conditions

Merchant (1944), (1945A) and (1945B) derived a model for determining the cutting forces when machining steel. The model was based on elastic-plastic deformation and a continuous chip formation (ductile cutting). The model included internal and external friction and shear strength, but no adhesion, gravity, inertia and pore pressures. Later Miedema (1987 September) extended this model with adhesion, gravity, inertial forces and pore water pressures. These models however only describe the so called Flow Type of cutting process, which is the ductile cutting process. The ductile cutting process requires a relatively large tensile strength (BTS) compared to the compressive strength (UCS) or shear strength. If the tensile strength is not large enough, brittle failure based on tensile failure may occur. This paper describes a new method of determining the cutting forces resulting from brittle failure, still based on the original ductile models, but with a correction for the stresses. This new model can be used for Deep Sea Mining Applications. It is assumed that materials which behave brittle under atmospheric conditions will behave ductile under hyperbaric conditions.

scholarly journals Dynamic Tensile Strength of Dry and Saturated Hard Coal under Impact Loading

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1273
Author(s):  
Xianlei Zhu ◽  
Qing Li ◽  
Guihua Wei ◽  
Shizheng Fang
Keyword(s):  
Tensile Strength ◽  
High Speed ◽  
Shear Failure ◽  
Split Hopkinson Pressure Bar ◽  
Failure Process ◽  
Tensile Failure ◽  
Hard Coal ◽  
Control Group ◽  
Hopkinson Pressure Bar ◽  
Brazilian Disk

To evaluate the influence of water content on the hard coal dynamic behavior, the dynamic tensile properties of saturated coal Brazilian disk (BD) samples were studied using a split Hopkinson pressure bar system, and dry samples were also tested as a control group. In the range of impact speeds studied, the tensile strength of the saturated coal is lower than that of the dry specimen. A synchronized triggering high-speed camera was used to monitor the deformation and failure process of dry and saturated coal samples, allowing analysis of the failure stages and mechanism of dynamic BD test, the broken mode was classified into three types, which can be classified into unilateral tensile failure, bilateral or multilateral tensile failure, and shear failure. Finally, fragments smaller than 5 mm in diameter were statistically analyzed. There is less debris in range of 0–5.0 mm for the saturated coal sample than for the dry coal. This study provides some information about the dynamic response of the hard coal for the relevant practical engineering.

Direct tensile failure of cementitiously stabilized crushed rock materials

2007 ◽  
Vol 44 (2) ◽  
pp. 231-240 ◽  
Author(s):  
Srijib Chakrabarti ◽  
Jayantha Kodikara
Keyword(s):  
Tensile Strength ◽  
Tensile Strain ◽  
Dry Weight ◽  
Basaltic Rock ◽  
General Purpose ◽  
Tensile Failure ◽  
Crushed Rock ◽  
Tensile Behaviour ◽  
Curing Time ◽  
Direct Tensile

Tensile behaviour plays a very significant role in the performance of cement-stabilized pavements under traffic, as well as under environmental loading. This paper reports the results of direct tensile strength tests undertaken using new equipment. The tests were performed on specimens of crushed basaltic rock stabilized with three binders, namely, general purpose Portland (GP) cement, general blended (GB) cement, and alkali activated slag (AAS), with application rates of 2%, 3%, and 4% by dry weight. Some tests were conducted by adding 6% and 15% highly plastic clay to crushed basaltic rock. The tests showed that while the tensile strength increased with curing time, the failure tensile strain decreased. The ratio of unconfined compressive strength to tensile strength decreased with curing time, but it stabilized within the range 8–12 after about 7 days of curing. For AAS and GB cement, the failure tensile strain decreased with curing time, stabilizing at about 50 microstrains after 7 days of curing, whereas for GP cement, the failure tensile strain did not change significantly during curing, displaying a value around 40 microstrains. The test results also indicated that the presence of reactive fine-grained soil may have had a significant adverse effect on the potential for cracking in the stabilized pavement materials.Key words: pavement materials, cement stabilization, tensile strength, cracking potential.

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