OPTIMIZATION OF TAB GEOMETRY TO MINIMIZE LONGITUDINAL STRESS CONCENTRATION DURING TENSILE TESTING OF UNIDIRECTIONAL CFRP

2021 ◽  
Author(s):  
SHAILEE UPADHYAY ◽  
FRANCISCO MESQUITA ◽  
BABAK FAZLALI ◽  
LARISSA GORBATIKH ◽  
YENTL SWOLFS
Keyword(s):  
Tensile Strength ◽  
Tensile Testing ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Longitudinal Stress ◽  
Stress Concentrations ◽  
Premature Failure ◽  
Longitudinal Tensile Strength ◽  
Working Zone ◽  
Gauge Section

A uniaxial tensile test is a useful method for determination of material properties, especially longitudinal tensile strength. To accurately derive the longitudinal tensile strength, it is desired that the specimen fails in in the gauge section defined here as ‘working zone’. Unidirectional (UD) composites require use of end tabs during this tensile testing to avoid damage to the specimen due to grip serrations. The grip pressure, along with sudden geometry change at the edge of end tabs leads to longitudinal stress concentrations. The conventionally used rectangular and tapered end tabs suffer from these longitudinal stress concentrations under the edge of end tabs, causing premature failure of specimen outside of the working zone. In the present paper, a simulation study is performed for comparison of conventional end tabs with hybrid specimen geometry [1] and a novel arrow-shaped end tab geometry to determine the effect of end tab geometry on longitudinal stress concentrations. The study is focused on high modulus carbon fibre HS40/epoxy UD (0°) composite. The numerical model replicates the actual set-up for uniaxial tensile testing, including contact interactions between testing machine components. The simulation results are used to further optimise the geometry and provide recommendations to eliminate or minimise longitudinal stress concentrations.

Tensile Testing

2004 ◽  
Keyword(s):  
Tensile Testing ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Adhesively Bonded Joints ◽  
Design And Manufacturing ◽  
Data Tables ◽  
Reference Section

Tensile Testing, Second Edition is a comprehensive guide to the uniaxial tensile test and its use in determining the mechanical properties and behaviors of materials. The first six chapters cover the fundamentals of tensile testing, including the methodology, the equipment used, the effect of tensile loading on metals, the interpretation of data, and the role of tensile testing in design and manufacturing. The next six chapters deal with the testing of different classes of engineering materials, namely metals, plastics, elastomers, ceramics, and composites, and fabricated structures such as weldments and bolted and adhesively bonded joints. The book also includes three chapters on the nuances of tensile testing at extreme temperatures and strain rates and a reference section with data tables. For information on the print version, ISBN 978-0-87170-806-9, follow this link.

Design and development of aluminum alloy 6061-T6 pressure vessel liner for aerospace applications: A technical brief

2021 ◽  
pp. 146442072110651
Author(s):  
R Pramod ◽  
N Siva Shanmugam ◽  
C K Krishnadasan ◽  
G Radhakrishnan ◽  
Manu Thomas
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloy ◽  
Weld Metal ◽  
Tensile Test ◽  
Pressure Vessel ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Aluminum Alloy 6061 ◽  
Custom Made ◽  
Alloy 6061

This work mainly focuses on designing a novel aluminum alloy 6061-T6 pressure vessel liner intended for use in launch vehicles. Fabrication of custom-made welding fixtures for the assembly of liner parts, namely two hemispherical domes and end boss, is illustrated. The parts of the liner are joined using the cold metal transfer welding process, and the welding trials are performed to arrive at an optimized parametric range. The metallurgical characterization of weld joint reveals the existence of dendritic structures (equiaxed and columnar). Microhardness of base and weld metal was 70 and 65 HV, respectively. The tensile strength of base and weld metal was 290 and 197 MPa, respectively, yielding a joint efficiency of 68%. Finite-element analysis of a uniaxial tensile test was performed to predict the tensile strength and location of the fracture in base and weld metal. The experimental and predicted tensile test results were found to be in good agreement.

A Method for Estimating Uncertainty of Indentation Tensile Properties in Instrumented Indentation Test

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Eun-chae Jeon ◽  
Joo-Seung Park ◽  
Doo-Sun Choi ◽  
Kug-Hwan Kim ◽  
Dongil Kwon
Keyword(s):  
Tensile Strength ◽  
Yield Strength ◽  
Tensile Test ◽  
Tensile Properties ◽  
Indentation Test ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Instrumented Indentation ◽  
Estimation Model ◽  
Instrumented Indentation Test

The instrumented indentation test, which measures indentation tensile properties, has attracted interest recently because this test can replace uniaxial tensile test. An international standard for instrumented indentation test has been recently legislated. However, the uncertainty of the indentation tensile properties has never been estimated. The indentation tensile properties cannot be obtained directly from experimental raw data as can the Brinell hardness, which makes estimation of the uncertainty difficult. The simplifying uncertainty estimation model for the indentation tensile properties proposed here overcomes this problem. Though the influence quantities are generally defined by experimental variances when estimating uncertainty, here they are obtained by calculation from indentation load-depth curves. This model was verified by round-robin test with several institutions. The average uncertainties were estimated as 18.9% and 9.8% for the indentation yield strength and indentation tensile strength, respectively. The values were independent of the materials’ mechanical properties but varied with environmental conditions such as experimental instruments and operators. The uncertainties for the indentation yield and tensile strengths were greater than those for the uniaxial tensile test. These larger uncertainties were caused by measuring local properties in the instrumented indentation test. The two tests had the same tendency to have smaller uncertainties for tensile strength than yield strength. These results suggest that the simplified model can be used to estimate the uncertainty in indentation tensile properties.

scholarly journals Tensile Properties of Polymer Repair Materials - Effect of Test Parameters

2015 ◽  
Vol 1129 ◽  
pp. 445-452
Author(s):  
Z. Kamil ◽  
G. Andrzej ◽  
C. Sandra ◽  
A.J. Barroso
Keyword(s):  
Tensile Strength ◽  
Tensile Test ◽  
Modulus Of Elasticity ◽  
Deformation Rate ◽  
Effect Of Temperature ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Sample Shape ◽  
Repair Materials ◽  
Test Parameters

In this research, five types of polymer repair materials were selected for investigation of the influence of sample shape, deformation rate and test temperature on the mechanical properties determined with an uniaxial tensile test. The results showed the clear effect of measurement conditions on tensile strength, elongation and modulus of elasticity. The highest tensile strength and modulus of elasticity were exhibited by epoxy resin for the filling of concrete cracks, which achieved 1% elongation. The lowest coefficient of dispersion characterized the results of tensile test carried out using dumbbell samples at a deformation rate of 50 mm/min. The effect of temperature varied with the material type.

Biomechanical and Elastographic Analysis of Mesenchymal Stromal Cell Treated Tissue Following Surgery

2010 ◽  
Vol 132 (7) ◽  
Author(s):  
Hazel Marie ◽  
Yong Zhang ◽  
Jeremy Heffner ◽  
Heath A. Dorion ◽  
Diana L. Fagan
Keyword(s):  
Mechanical Property ◽  
Tensile Test ◽  
Tensile Testing ◽  
Recovery Period ◽  
Strain Analysis ◽  
Biomechanical Properties ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Ongoing Research ◽  
Uniaxial Tensile Testing

Hernia repair continues to be a problem facing surgeons today, particularly because of the high incidence of reoccurrence. This work presents preliminary data of a pioneering effort to investigate the effect of mesenchymal stromal cells (MSCs) on mechanical property enhancement in full thickness fascial defects. Heparinized MSCs harvested from a rabbit’s tibia/iliac crest were applied to two fascial defects on the rabbit’s abdominal wall, with two other defects acting as controls (no MSCs added). After an 8 week recovery period, the entire abdominal fascia was harvested for mechanical property testing and elastographic strain analysis. Preliminary results from uniaxial tensile testing indicate a significant increase in the modulus of toughness strain energy, with at least a 50% increase in the MSC treated defects as compared with the control defects. Results from the elastographic strain analysis show excellent correlation in the calibration of the elastography to the uniaxial tensile test, with nearly identical moduli of elasticity. In addition, the elastographs clearly show tissue property heterogeneity at all stages of tensile testing. The MSC treated tissue demonstrates promise of enhanced material properties over that of the nontreated tissue; testing and analysis is ongoing. The elastography provides pixel-level description of tissue property variations providing critical information on wound healing effectiveness that would be impossible with other methods. In the ongoing research, optical elastography, in combination with the traditional tensile test and tissue histology, will be used to characterize localized biomechanical properties directly within the defect area and to locate “crack” initiation and propagation sights as the material is strained to rupture.

scholarly journals Effects of Vehicle-Induced Vibrations on the Tensile Performance of Early Age PVA-ECC

2019 ◽  
Author(s):  
Xiaodong Zhang ◽  
Shuguang Liu ◽  
Changwang Yan ◽  
Xiaoxiao Wang ◽  
Huiwen Wang
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Correlation Analysis ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Early Age ◽  
Grey Correlation ◽  
Tensile Performance ◽  
Grey Correlation Analysis ◽  
The Impact

The purpose of this study was to conduct laboratory test programs on how much vehicle-induced vibrations during early ages affected the tensile performance of Polyvinyl alcohol-engineering cementitious composites (PVA-ECC). A self-improved device was used to simulate the vehicle-induced vibrations, and after vibrating with the designed variables, both a uniaxial tensile test and a grey correlation analysis were performed. The results indicated that: the effects of vehicle-induced vibrations on the tensile performance of early age PVA-ECC were significant, and they generally tended to be negative in this investigation. In particular, for all of the vibrated PVA-ECC specimens, the most negative age when vibrated occurred during the period between the initial set and the final set. In this period, the effects of the vibration duration on the tensile performance of the PVA-ECC tended to be negative overall, but the impact trend and the degree varied for the corresponding lengths of duration and levels of frequency. The cracking strength was the most sensitive to the variables in this investigation, and then it followed the ultimate tensile strength and strain. The grey correlation analysis was applicable in analyzing the effects of vehicle-induced vibrations on the tensile performance of early age PVA-ECC.

Effects of Heat Treatment on Microstructures and Mechanical Properties of Ti-38644 Alloy for Aerospace Fasteners

2018 ◽  
Vol 913 ◽  
pp. 109-117 ◽  
Author(s):  
Qing Yun Zhao ◽  
Si Rui Cheng ◽  
Li Dong Wang ◽  
Li Min Dong ◽  
Feng Lei Liu
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Tensile Strength ◽  
Solution Temperature ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Air Cooling ◽  
Β Phase ◽  
Α Phase

The effects of heat treatment on microstructure and mechanical properties of Ti-38644 alloy were investigated by scanning electron microscope (SEM) and transmission electron microscopy (TEM) as well as uniaxial tensile test. The results show that when the solution temperature is lower than 845°C, the microstructure of Ti-38644 alloy is equiaxed β phase with the grain size of 20μm, and the tensile strength is about 960MPa. As raising solution temperature to 860°C, the grain size of Ti-38644 alloy increases to 100μm and the tensile strength decreased to 870MPa. There are a large number of secondary α phase precipitated from the grain boundaries and within grain of β phase undergoing aging treatment. Secondary α phase coarsens with increasing the aging temperature, leading to the decrease of tensile strength. After solution treatment at 815°C for 1.5h, water quenching plus aging at 520°C for 10h, air cooling, Ti-38644 alloy shows a better mechanical property with the tensile strength 1330MPa, elongation and reduction of area 10% and 45% respectively.

ANALISA KEKUATAN MEKANIS SAMBUNGAN LAS KAMPUH V TUNGGAL DAN V GANDA PADA BAJA KARBON RENDAH DENGAN PROSES PENGELASAN SMAW

2021 ◽  
Vol 12 (2) ◽  
pp. 103
Author(s):  
Sudarsono Sudarsono ◽  
Hidayat Hidayat ◽  
Aminur Aminur ◽  
Sarwo Pranoto ◽  
Prinob Aksar
Keyword(s):  
Tensile Strength ◽  
Bending Strength ◽  
Low Carbon Steel ◽  
Welding Process ◽  
Bending Test ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Low Carbon ◽  
Shielded Metal Arc Welding ◽  
Metal Arc Welding

Welding is one of the methods widely used in the joining of metals for structural elements. One of the factors that influence the strength of welded metals is types of welding joints. Suitability of the type of welding joint with geometries of base metals is required to obtain welded metal products with optimum properties. In this study an attempt is made to investigate mechanical properties of welded metals with two different types of joints (single-V and double-V) using the shielded metal arc welding (SMAW) process. Low carbon steel with bevel angle of 60° was used in this study. Welding process was performed using current of 70 A with a constant welding speed. The flexural properties and uniaxial tensile properties are studied by three-point bending test and uniaxial tensile test respectively. Test results show that the tensile strength and the bending strength of single-V specimens is 521.64 N/mm2 and 525.11 N/mm2 respectively. In addition, the tensile strength and the bending strength of double-V specimens is 517.33 N/mm2 and  504.24 N/mm2 respectively

Application of Pre-Strained Steels in Empirical Correlation Between Small Punch Test and Uniaxial Tensile Test

2020 ◽  
Vol 12 (6) ◽  
pp. 892-898
Author(s):  
Gang Liu ◽  
Kai-Shu Guan ◽  
Ji-Ru Zhong
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Tensile Test ◽  
Maximum Load ◽  
Empirical Correlation ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Small Punch Test ◽  
Punch Test

In order to research the method of strength empirical correlation between conventional small punch test (SPT) and uniaxial tensile test, a series of austenitic stainless steel including pre-strained SUS304 have been tested in this study. The conventional SPT is conducted on a small disc-shaped specimen whose edge is firmly gripped by a die, and the specimen is deformed by a punch. The method of empirical correlation between SPT and uniaxial tensile test is a direct way to obtain the mechanical properties of materials. Through establishing the strength empirical correlation, it can achieve to calculate the strength of material by SPT which is nondestructive to equipments. However, the per-strained steels have never been tested in this method. This study is to fill that gap and to obtain the empirical correlation between SPT and uniaxial tensile test with pre-strained steel. In this study, a series of austenitic stainless steel including SUS304 after different levels of pre-strain were tested successively by uniaxial tensile test and SPT. It is found that the tensile strength obtained from uniaxial tensile test increases with the increasing levels of pre-strain. However, the maximum load obtained from prestrained SPT specimen does not increase with the increasing levels of pre-strain. It is contradictory to the linear relation between maximum load and tensile strength. According to the analysis of conventional discshaped SPT specimen, the directions of maximum load obtained from SPT and tensile strength from tensile test are not uniform. It results in the non-linearity between the maximum load and the tensile strength with pre-strained steel, and it indicates the pre-strained steel cannot be applied to the conventional disc-shaped SPT specimen. Furthermore, the prestrained steel is a typical kind of anisotropic material. Therefore, extending to anisotropic material, the conventional disc-shaped SPT specimen is not suitable for the method of strength empirical correlation.

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