Effects of Notch Radius and Thickness on the Tensile Strength and Fracture Mechanisms of Al6061-T6 Plate Specimens

2021 ◽  
Author(s):  
Liang Wang ◽  
Xiao Du ◽  
Nak-Sam Choi
Keyword(s):  
Tensile Strength ◽  
Fracture Mechanisms ◽  
Notch Radius

scholarly journals Dynamic Tensile Properties of CFRP Manufactured by PCM and WCM: Effect of Strain Rate and Configurations

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1491
Author(s):  
Yujin Yang
Keyword(s):  
Tensile Strength ◽  
Strain Rate ◽  
Tensile Properties ◽  
Strain Rate Sensitivity ◽  
Failure Strain ◽  
Dynamic Performance ◽  
Rate Sensitivity ◽  
Fracture Mechanisms ◽  
Reinforced Plastic ◽  
Dynamic Tensile Properties

Carbon fiber-reinforced plastic (CFRP) is a promising material to achieve lightweight automotive components. The effects of the strain rate and configurations of CFRP on dynamic tensile properties have not yet been fully explored; thus, its lightweight benefits cannot be maximized. In this paper, the dynamic tensile properties of CFRPs, tested using two different processes with two different resins and four different configurations, were studied with a strain rate from 0.001 to 500 s−1. The tensile strength, modulus, failure strain, and fracture mechanism were analyzed. It was found that the dynamic performance enhances the strength and modulus, whereas it decreases the failure strain. The two processes demonstrated the same level of tensile strength but via different fracture mechanisms. Fiber orientation also significantly affects the fracture mode of CFRP. Resins and configurations both have an influence on strain rate sensitivity. An analytic model was proposed to examine the strain rate sensitivity of CFRPs with different processes and configurations. The proposed model agreed well with the experimental data, and it can be used in simulations to maximize the lightweight properties of CFRP.

scholarly journals Effect of Different Types of Block Copolymers on Morphology, Mechanical Properties, and Fracture Mechanisms of Bisphenol-F Based Epoxy System

2019 ◽  
Vol 3 (3) ◽  
pp. 68 ◽  
Author(s):  
Bajpai ◽  
Wetzel
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tensile Strength ◽  
Block Copolymers ◽  
Fracture Energy ◽  
Plastic Zone Size ◽  
Fracture Mechanisms ◽  
Epoxy System ◽  
Bisphenol F ◽  
Different Types

The effect of adding different types of soft block copolymer on the tensile properties, fracture mechanic properties, and thermo-mechanical properties of bisphenol F based epoxy resin were studied. Two different self-assembling block copolymers, (a) constituting of a center block of poly (butyl acrylate) and two side blocks of poly (methyl) methacrylate-co-polar co-monomer (BCP 1) and (b) poly(ethylene oxide)-b-poly(butylene oxide) (PEO-PBO) diblock copolymer (BCP 2), were used with an epoxy-hardener system. The maximum fracture toughness and fracture energy were measured as KIc = 2.75 MPa·m1/2 and GIc = 2.37 kJ/m2 for the 10 wt % of BCP 1 modified system, which were 366% and 2270% higher in comparison to reference epoxy system, and a 63% reduction in tensile strength was also observed. Similarly, for BCP2 modified systems, the maximum value of KIc = 1.65 MPa·m1/2 and GIc = 1.10 kJ/m2 was obtained for epoxy modified with 12 wt % of BCP2 and a reduction of 32% in tensile strength. The fracture toughness and fracture energy were co-related to the plastic zone size for all the modified systems. Finally, the analysis of the fracture surfaces revealed the toughening micro-mechanisms of the nanocomposites.

Experimental evaluation and modified Weibull characterization of the tensile behavior of tri-component elastic-conductive composite yarn

2017 ◽  
Vol 88 (10) ◽  
pp. 1138-1149 ◽  
Author(s):  
Yong Wang ◽  
Weidong Yu ◽  
Fumei Wang
Keyword(s):  
Tensile Strength ◽  
Strength Distribution ◽  
Gauge Length ◽  
Distribution Model ◽  
Fracture Mechanisms ◽  
Extension Rate ◽  
Strengthening Effect ◽  
Conductive Composite ◽  
Practical Applications ◽  
Composite Yarn

In order to clarify the effects of the extension rate and gauge length upon the distribution of tensile strength of tri-component elastic-conductive composite yarn (t-ECCY), experimental as well as theoretical studies have been performed in this paper. Influences of the extension rate and gauge length are highlighted. The yarn exhibits an extension-rate strengthening effect, and the higher extension rate results in a higher strength and fracture strain, irrespective of the gauge length considered, and vice versa. Expressed in terms of gauge length, yarn tenacity shows a drop for a longer testing length at all extension rates, based on the weakest-link theory. A modified two-parameter Weibull strength distribution model, taking into account the effects of extension rate and gauge length, can be reasonably used to quantify the degree of variability in tensile strength and to obtain the individual Weibull parameters for practical applications. Different fracture mechanisms of the t-ECCY are demonstrated at lower and higher extension rates. A “cascade-like” break happens at lower extension rates due to inner sliding, weaker interactive transverse force of individual fibers, and sufficient time available for the fiber realignment. Nevertheless, a “chimney-like” break dominates at higher extension rates by virtue of the reduced reorientation of some disordered fibers and intensive instant impact force of the stainless steel filament component along the load direction.

Investigation of nano-hybridization effects on low velocity impact behaviors of basalt fiber reinforced composites

2020 ◽  
pp. 002199832094964
Author(s):  
İbrahim Demirci ◽  
Ahmet Avcı ◽  
Mehmet Turan Demirci
Keyword(s):  
Tensile Strength ◽  
Epoxy Composites ◽  
Low Velocity Impact ◽  
Maximum Force ◽  
Fracture Mechanisms ◽  
Fiber Reinforced ◽  
Epoxy Nanocomposites ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact

In general the nanoparticles increase the mechanical and impact behaviors of fiber reinforced polymer based composites. However, the effects of the hybridization of nanoparticles and their reasons over the nano scale fracture mechanisms have not been adequately studied for fiber reinforced composites. In this study, the low velocity impact responses and the mechanical behaviors were investigated for 4%wt. SiO2 nanoparticles filled BFR/Epoxy nanocomposites, 0.5%wt. MWCNTs filled BFR/Epoxy nanocomposites, 4%wt. SiO2 nanoparticles and 0.5%wt. MWCNTs nano-hybrid filled BFR/Epoxy nanocomposites and unfilled BFR/Epoxy composites. The tensile and low velocity impact tests at 10 J and 20 J of energy levels were applied to nanoparticles, nano-hybrid and unfilled BFR/Epoxy composites in order to define the effects of nanoparticles and nano-hybrid particles on the impact and mechanical features according to in accordance with ASTM D3039/D3039M-14 and ASTM D7136/7136M standards. It was observed that SiO2 nanoparticles addition to BFR/Epoxy for both 10 J and 20 J showed the highest tensile strength, maximum force, rebound energy and the lowest displacements and absorbed energy. SiO2+MWCNTs nano-hybrid addition to BFR/Epoxy improved higher low velocity impact responses and tensile strength than MWCNTs addition. The specimens of unfilled BFR/Epoxy composites showed the lowest tensile strength and maximum force and the highest maximum force, displacements and absorbed energy. Microscope and SEM analyses demonstrated that minimum failures like fiber breakages, delamination and debonding were observed by filling SiO2 nanoparticles provided the nano scale fracture mechanisms. In addition MWCNTs hybridization with SiO2 nanoparticles minimizes negative effects of MWCNTs micro size length and improved the impact and mechanical behaviors.

scholarly journals Ductile Fracture Behavior of Notched Aluminum Alloy Specimens under Complex Non-Proportional Load

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1598 ◽  
Author(s):  
Łukasz Derpeński
Keyword(s):  
Aluminum Alloy ◽  
Ductile Fracture ◽  
Tensile Force ◽  
Testing Machine ◽  
Fracture Initiation ◽  
Measuring System ◽  
Fracture Mechanisms ◽  
Torsional Angle ◽  
Notch Radius ◽  
Contact Tracking

The paper presents an experimental investigation of the ductile fracture of specimens with different circumferential notches. Specimens made from ENAW_2024-T351 aluminum alloy were subjected to non-proportional tension–torsion loading. The tests were carried out on an MTS testing machine coupled with the ARAMIS 3D 4M vision measuring system, enabling simultaneous non-contact tracking of the elongation and torsional angle of the measurement base. Depending on the assumed notch radius and the non-proportionate load scheme, the critical tensile force and torsional moments that caused the fracture initiation of the specimen were determined. A significant effect of load configurations and notch radius on the shape of the fracture surface as well as the fracture mechanisms causing the failure of specimens was demonstrated. The equation describing the configuration of critical loads for specimens with different notch radii was applied.

Experimental simulation of bending damage of silicon nitride yarn during 3D orthogonal fabric forming process

2021 ◽  
pp. 152808372110106
Author(s):  
Ning Wu ◽  
Shuai Li ◽  
Meiyue Han ◽  
Chao Zhu ◽  
Yanan Jiao ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Silicon Nitride ◽  
Strength Loss ◽  
Fracture Probability ◽  
Experimental Simulation ◽  
Fracture Mechanisms ◽  
Forming Process ◽  
Yarn Tension ◽  
Fabric Thickness ◽  
Bending Fracture

The aim of this study executed on Silicon Nitride (Si3N4) yarn is to examine some bending damage behaviors and fracture mechanisms that occur during the 3D orthogonal fabric forming process. A three point bending experiment device has been developed in order to simulate the Z-binder yarn bending condition. The effects of weft density, fabric thickness, and yarn tension have been studied. The Weibull analysis of the tensile strength show that the bending damage increases with the increase of weft density, fabric thickness, and yarn tension. The resulting bending damage causes a reduction in yarn strength of between 2.5 and 17.2% depending on the bending parameters of yarn. The growth of the fibrillation area also reflects similar trends with tensile strength loss rate. The fibrillation length produced by the yarns is mostly distributed within the range of 0.3 to 0.9 mm. A comparison of the calculation result to experimental data shows the bending fracture probability of filaments inside yarn are less than that of monofilament. The tensile and bending fracture of Si3N4 filaments exhibit typical brittle fracture characteristics.

scholarly journals Off-Axial Tensile Properties of Precontraint PVDF Coated Polyester Fabrics under Different Tensile Rates

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Lanlan Zhang
Keyword(s):  
Tensile Strength ◽  
Linear Relationship ◽  
Failure Modes ◽  
Tensile Tests ◽  
Woven Fabrics ◽  
Uniaxial Tensile ◽  
Fracture Mechanisms ◽  
Axial Angle ◽  
Axial Tensile ◽  
Research Objects

Two types of Precontraint PVDF coated polyester are taken as the research objects. A series of uniaxial tensile tests were carried out to study the tensile performances of the specimens in eleven in-plane directions including 0°, 5°, 15°, 25°, 35°, 45°, 55°, 65°, 75°, 85°, and 90°, and six tensile rates (10 mm/min, 25 mm/min, 50 mm/min, 100 mm/min, 200 mm/min, and 500 mm/min) were also considered. The corresponding failure modes and fracture mechanisms were discussed, and the relationships between tensile strength and strain at break and tensile rate and off-axial angles were obtained. Results show that the Precontraint PVDF coated woven fabrics are typically anisotropic. With off-axial angle increasing, the tensile strength decreases while the strain at break increases. Three failure modes can be observed, including failure of yarns pulled out, yarns fracture, and mixture failure. With tensile rate increasing, the tensile strength increases slightly while the strain at break decreases. The tensile strength and strain at break show good linear relationship with tensile rate’s logarithm.

Microstructure and mechanical properties of reinforced polyamide 12 composites prepared by laser additive manufacturing

2019 ◽  
Vol 25 (6) ◽  
pp. 1127-1134 ◽  
Author(s):  
Yanhui Liu ◽  
Lingjie Zhu ◽  
Lei Zhou ◽  
Yongjiu Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Selective Laser Sintering ◽  
Tensile Fracture ◽  
Fracture Mechanisms ◽  
Strengthening Effect ◽  
Content Type ◽  
Tensile Fracture Surface ◽  
Polyamide 12 ◽  
Microstructure And Mechanical Properties

Purpose This paper aims to explore the influence of the reinforcement included either glass beads (GBs) or carbon fiber (CF) on the reinforced polyamide 12 (PA12) composite samples prepared by selective laser sintering (SLS). Design/methodology/approach In this paper, the microstructure and mechanical properties are investigated, and the results are compared with those obtained for non-reinforced pure PA12 samples prepared by SLS. Findings The tensile fracture surface of the non-reinforced pure PA12 sample presents strong micro-deformation within the crack origination zone between the melted PA12 matrix and the un-melted PA12 particle cores. As a result, the pure PA12 sample exhibits the greatest maximum elongation. The maximum tensile strength is obtained for the CF reinforced sample because of the strengthening effect of CF and the relatively good bonding between CFs and the PA12 matrix. The minimum tensile strength is obtained for the GB reinforced PA12 sample because of the relatively weak bonding between GBs and the PA12 matrix. Originality/value These results demonstrate that the characteristics of the interfaces between the reinforcement and the PA12 matrix have an important influence on the fracture mechanisms and mechanical properties of PA12 composites fabricated by SLS.

Morphology and Mechanical Properties of Epoxy/Alumina Nanocomposites

2006 ◽  
Vol 312 ◽  
pp. 233-236 ◽  
Author(s):  
Ke Wang ◽  
Pascal Ogier ◽  
Chauhari Wuiwui Tjiu ◽  
Chaobin He
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tensile Strength ◽  
Epoxy Resin ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Fracture Mechanisms ◽  
Elongation At Break ◽  
Filler Dispersion ◽  
Morphology And Mechanical Properties

Alumina nano-crystals were dispersed in epoxy resin via different approaches. The effects of filler dispersion on the mechanical properties of the epoxy/alumina nanocomposites were studied. The fracture mechanisms are investigated using SEM. The results show that the Young’s modulus, tensile strength, elongation at break and fracture toughness of epoxy were improved dramatically with the incorporation of well-dispersed alumina nano-crystals. The poorly-dispersed nano-crystals, however, showed little effects on the mechanical properties.

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