The Influence of Loading Rate on the Ultimate Properties and Fracture Mechanism of Styrenic Thermoplastic Elastomers

2008 ◽  
Vol 41-42 ◽  
pp. 91-97
Author(s):  
Qiu Mei Zeng ◽  
Jeremy W. Leggoe
Keyword(s):  
Tensile Strength ◽  
Fracture Surface ◽  
Strain Rate ◽  
Loading Rate ◽  
Chain Scission ◽  
Thermoplastic Elastomers ◽  
Tensile Fracture ◽  
Void Coalescence ◽  
Pull Out ◽  
Poly Ethylene

The influence of loading rate on the tensile fracture of polystyrene-polyisoprenepolystyrene (SIS) and polystyrene-poly(ethylene-co-butylene)-polystyrene (SEBS) has been investigated. The tensile strength of SIS initially increased with increasing strain rate, eventually reaching a plateau at elevated strain rates. In contrast, the tensile strength of SEBS was relatively unaffected by strain rate. The fracture surfaces of the tensile test specimens were examined by scanning electron microscopy. The fracture surface morphologies indicated that fracture initiated via cavitation, followed subsequently by void coalescence and catastrophic fracture. For both materials there was no qualitatively obvious change in fracture surface morphology with increasing strain rate. The results indicate that the ultimate strength of styrenic thermoplastic elastomers is governed by the nature of the dominant failure mechanism at the molecular scale; when chain scission dominates, the tensile strength is independent of the strain rate, but when chain pull-out dominates, the tensile strength increases with increasing strain rate.

Fracture Behavior of an AlMgMnSc Alloy at Different Temperatures

2021 ◽  
Vol 1016 ◽  
pp. 292-296
Author(s):  
Yuliya Igorevna Borisova ◽  
Diana Yuzbekova ◽  
Anna Mogucheva
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Brittle Fracture ◽  
Fracture Surface ◽  
Strain Rate ◽  
Fracture Behavior ◽  
Fine Grained ◽  
Angular Pressing ◽  
Different Temperatures ◽  
Elongation To Failure

An Al-4.57Mg-0.35Mn-0.2Sc-0.09Zr (wt. %) alloy was studied in the fine-grained state obtaining after equal channel angular pressing. The mechanical behavior of alloy at the temperatures 173 K, 298 K and 348 K and at strain rate 1×10–3 s–1 is studied. Increase of the temperature testing from 173 K to 348 K decreases the yield stress by 80 MPa, the ultimate tensile strength by 60 MPa while elongation-to failure increases by a factor of 1.4. It was found that at temperatures of 298 and 173 K, the studied alloy mainly demonstrates the mode of ductile fracture, and at a temperature of 348 K the mechanism can be described as mixed ductile-brittle fracture. It was also established that of the studied alloy is the temperature dependence of the size of the dimples on the fracture surface. The formation of smaller dimples in the samples deformed at 298 K was observed.

Mechanical Properties and Fracture Study of Alumina Dispersion Hardened Copper-Based Nano-Composite at Elevated Temperatures

2013 ◽  
Vol 829 ◽  
pp. 583-588 ◽  
Author(s):  
Ali Dalirbod ◽  
Yahya A. Sorkhe ◽  
Hossein Aghajani
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Fracture Surface ◽  
Yield Strength ◽  
Elevated Temperatures ◽  
Tensile Tests ◽  
Testing Temperature ◽  
Optical Microscope ◽  
Tensile Fracture ◽  
Different Temperatures

Alumina dispersion hardened copper-base composite was fabricated by internal oxidation method. The high temperature tensile fracture of Cu-Al2O3 composite was studied and tensile strengths were determined at different temperatures of 600, 680 and 780 °C. Microstructure was investigated by means of optical microscope and field emission scanning electron microscope (FESEM) with energy dispersive spectroscopy (EDS). Results show that, ultimate tensile strength and yield strength of copper alumina nanocomposite decrease slowly with increasing temperature. The yield strength reaches 119 MPa and ultimate tensile strength reaches 132 MPa at 780 °C. Surface fractography shows a dimple-type fracture on the fracture surface of the tensile tests where dimple size increases with increasing testing temperature and in some regions brittle fracture characteristics could be observed in the fracture surface.

In-Situ Estimates of the Tensile Strength of Snow Utilizing Large Sample Sizes

1979 ◽  
Vol 22 (87) ◽  
pp. 321-329 ◽  
Author(s):  
David M. McClung
Keyword(s):  
Tensile Strength ◽  
Loading Rate ◽  
New Method ◽  
Tensile Fracture ◽  
Sample Sizes ◽  
Experimental Procedure ◽  
Large Sample ◽  
Sample Density ◽  
Average Sample

AbstractExperimental procedure and measured estimates of the tensile strength of snow are given by a new method utilizing large sample sizes of naturally deposited snow. Data are presented as a function of average sample density, temperature, loading rate, and snow type. The results show less scatter in the data than previous in-situ estimates and lower mean strength values as a function of density. The relevance of the data to tensile fracture as observed in slab avalanche release is discussed.

Study of Wettability of Vinyl Resin on Carbon Fiber

2012 ◽  
Vol 217-219 ◽  
pp. 157-160
Author(s):  
Hong Qiang Sun ◽  
Xiao Qing Wu
Keyword(s):  
Tensile Strength ◽  
Carbon Fiber ◽  
Fracture Surface ◽  
Epoxy Resin ◽  
Tensile Modulus ◽  
Epoxy Composites ◽  
Tensile Fracture ◽  
Interface Adhesion ◽  
Tensile Fracture Surface ◽  
Tensile Performance

The tensile performance of the vinyl resin casting body, epoxy resin casting body, carbon fiber(CF) reinforced vinyl composites and CF/epoxy composites has been presented. The morphology of tensile fracture surface of CF/epoxy and CF/vinyl has been compared, and the interface adhesion has been analysed. The results show the tensile strength for vinyl resin casting body is lower than epoxy resin casting body’s, the tensile modulus of them are close. But the tensile strength and modulus of CF/vinyl composites are both close to CF/epoxy composites. And the vinyl has the better interface adhesion and wettability on CF than epoxy.

Effect of Microstructure on Formation of Ductile Fracture Surface in Steel Plate

2011 ◽  
Vol 409 ◽  
pp. 678-683
Author(s):  
Tomoaki Fukahori ◽  
Shinichi Suzuki ◽  
Naoya Yamada ◽  
Masatoshi Aramaki ◽  
Osamu Furukimi
Keyword(s):  
Tensile Strength ◽  
Fracture Surface ◽  
Surface Morphology ◽  
Ductile Fracture ◽  
Fracture Property ◽  
Deformation Energy ◽  
Steel Plates ◽  
Void Coalescence ◽  
Fracture Properties ◽  
Fractured Surface

In recent years, high strength steel plates for building and pipelines have been required to improve ductile fracture properties, assuming ground deformation in earthquake-prone region. The ductile fracture is performed by the result from coalescence of micro-voids followed by the nucleation and growth [1]. Fractured surface morphology reflects the void coalescence process, so it is important to consider the relationship between the fracture surface morphology and the micro-voids formation beneath the fractured surface to consider the ductile fracture properties. The voids nucleate sites are mainly particles such as inclusions or precipitates, and grain boundries. These voids grow and coalesce according to three modes. The first mode is directly coalescence of voids followed by growth [2]. The second one is the coalescence of voids caused by shear deformation followed by internal necking between voids [3]. The third one is the coalescence of voids caused by micro-voids nucleation in shear band between two larger voids [4]. It is expected that these modes influence local elongation property which is one of the indices for ductile fracture property through the formation of fractured surface. In this study, local deformation energy which is measured by load-displacement curve in tensile test is examined by focusing the voids nucleation, growth and coalescence, for high tensile strength plates of TS480-830MPa which is controlled by the microstructure through the cooling rate of heat treatment. The deformation energy is useful to consider the ductile fracture property of steel plates which have a different tensile strength.

In-Situ Estimates of the Tensile Strength of Snow Utilizing Large Sample Sizes

1979 ◽  
Vol 22 (87) ◽  
pp. 321-329 ◽  
Author(s):  
David M. McClung
Keyword(s):  
Tensile Strength ◽  
Loading Rate ◽  
New Method ◽  
Tensile Fracture ◽  
Sample Sizes ◽  
Experimental Procedure ◽  
Large Sample ◽  
Sample Density ◽  
Average Sample

AbstractExperimental procedure and measured estimates of the tensile strength of snow are given by a new method utilizing large sample sizes of naturally deposited snow. Data are presented as a function of average sample density, temperature, loading rate, and snow type. The results show less scatter in the data than previousin-situestimates and lower mean strength values as a function of density. The relevance of the data to tensile fracture as observed in slab avalanche release is discussed.

Effects of TIG Process on Corrosion Resistance of 321 Stainless Steel Welding Joint

2013 ◽  
Vol 749 ◽  
pp. 173-179 ◽  
Author(s):  
Dan Hu ◽  
Shu Lin Li ◽  
Sheng Lu
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Fracture Surface ◽  
Strain Rate ◽  
Stress Corrosion ◽  
Intergranular Corrosion ◽  
Welding Joint ◽  
Maximum Tensile Strength ◽  
Stainless Steel Welding

In this paper, the effects of different TIG welding parameters on corrosion resistance of 321austenitic stainless steel welding joint were studied. Intergranular corrosion, stress-strain curves of SSRT and the fracture surface of the welding joint were investigated by means of intergranular corrosion test, SCC test and SEM. The results showed that the intergranular corrosion cracks did not occur for all joints welded in the range of TIG welding current of 130A~190A. In pure water at room temperature, strain rate at the range of 1×10-5 s-1~1×10-6 s-1 had little effect on the maximum tensile strength of the material under the same welding conditions and the time of joint fracture increased as the strain rate decreased. At strain rate of 1×10-6 s-1, the maximum tensile strength of the joint welded in the current of 130A and 150A decreased significantly in the dyeing assistant and presented stress corrosion sensitivity. Joints welded in the current of 170A and 190A, showed excellent resistance to stress corrosion. Through the analysis of the fracture surface of joints, the joint welded in current of 130A presented a tendency to brittle fracture, while the joints in the current of 170 A and190 A were characterized with ductile fracture.

scholarly journals Effect of Hot-Alkali Treatment on the Structure Composition of Jute Fabrics and Mechanical Properties of Laminated Composites

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1386 ◽  
Author(s):  
Xue Wang ◽  
Lulu Chang ◽  
Xiaolong Shi ◽  
Lihai Wang
Keyword(s):  
Mechanical Properties ◽  
Fracture Surface ◽  
Laminated Composites ◽  
Alkali Treatment ◽  
Tensile Fracture ◽  
Reinforced Composites ◽  
Tensile Fracture Surface ◽  
Pull Out ◽  
Jute Fibers ◽  
Jute Fabrics

In this study, jute fabrics/epoxy-laminated composites were fabricated via a simple and effective manual layering. Hot-alkali treatment was used to pretreat jute fabrics to improve their interfacial compatibility. The effects of hot-alkali treatment with five concentrations (2%, 4%, 6%, 8% and 10%) on the composition, crystallinity and surface morphology of jute fibers, were analyzed with the aids of Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), and the scanning electron microscope (SEM). The mechanical properties (tensile and flexural) of laminated composites, and the morphology of the tensile fracture surface, were analyzed. The results indicated that the crystallinity index (CI) and crystallite size (CS) of the cellulose in jute fibers were improved, and there were three stages for CI and CS with the increase of alkali concentrations. Hot-alkali treatment improved the mechanical properties of laminated composites, especially for the 6% NaOH-treated jute fabric reinforced. The tensile strength, flexural strength, tensile modulus and flexural modulus of 6% NaOH-treated fabrics reinforced composites were enhanced by 37.5%, 72.3%, 23.2% and 72.2%, respectively, as compared with those of untreated fabrics reinforced composites. The fiber pull-out and the gaps of the tensile fracture surface were reduced after hot-alkali treatment.

ZTA Ceramics Tensile Fracture Test Analysis under Ultrasonic Vibration Based on Nonlocal Theory

2012 ◽  
Vol 723 ◽  
pp. 456-459 ◽  
Author(s):  
Bo Zhao ◽  
Fan Chen ◽  
Jing Lin Tong
Keyword(s):  
Tensile Strength ◽  
Fracture Surface ◽  
Ultrasonic Vibration ◽  
Nonlocal Theory ◽  
Experimental Results ◽  
Tensile Fracture ◽  
Surface Microstructure ◽  
Fracture Test ◽  
Test Analysis ◽  
Theoretical Analyses

The nonlocal theory was introduced to establish the nonlocal constitutive model and analyze the effect of ultrasonic on the tensile strength and fracture surface microstructure. ZTA ceramics tensile fracture experimental results show that the tensile stress obviously reduces and the fracture changes under ultrasonic vibration. The experimental results are coincided with theoretical analyses.

The Influence of Specific Pressure on the Organization and Properties in Liquid Forging

2012 ◽  
Vol 430-432 ◽  
pp. 598-601
Author(s):  
Chun Li ◽  
Jia Xuan Wang ◽  
Hua Qing Miao
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Fracture Surface ◽  
Process Parameters ◽  
Tensile Fracture ◽  
Specific Pressure ◽  
Tensile Fracture Surface ◽  
Forging Process ◽  
Fracture Surface Analysis ◽  
And Performance

In this paper, based on the liquid forging part flange LY12, the influence of specific pressure on the organization and performance of the liquid forging part was studied through microstructure, mechanical properties and tensile fracture surface analysis methods, this article also has some guiding significance to the formulation of the best liquid forging process parameters. The results show that the tensile strength, hardness and elongation of the parts raise with the specific pressure increasing, the organization has also been significant refinement and improvement.

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