Pure shear fracture study in a brittle graphite material containing a U-notch

2013 ◽  
Vol 23 (6) ◽  
pp. 839-854 ◽  
Author(s):  
AR Torabi ◽  
M Fakoor ◽  
MA Darbani
Keyword(s):  
Shear Fracture ◽  
Pure Shear ◽  
Graphite Material ◽  
Fracture Study

Loading Direction Versus Crack Propagation Path in a Lead-Free Single Solder Joint Sample

2008 ◽  
Author(s):  
Feng Gao ◽  
Jianping Jing ◽  
Janine Johnson ◽  
Frank Z. Liang ◽  
Richard L. Williams ◽  
...  
Keyword(s):  
Solder Alloy ◽  
Mixed Mode ◽  
Shear Fracture ◽  
Pure Shear ◽  
Shear Loading ◽  
Propagation Path ◽  
Mixed Mode Loading ◽  
Cohesive Failure ◽  
Loading Direction ◽  
Shear Component

In this paper, single solder joints (SSJs) were subjected to moderate speed loading (5mm/sec) in different directions, from pure tensile, mixed mode to pure shear. Fracture surfaces from different loading directions were examined both experimentally and numerically. It is observed that intermetallic compound (IMC) is formed between the solder alloy and the Cu pad, and failure typically occurs at or near the solder/IMC/Cu interfaces on the board side. Pure tensile loading typically leads to interfacial fracture along the IMC/Cu interface. Mixed mode loading usually results in a mixture of interfacial and cohesive failure with crack propagating in a zigzag fashion between the solder/IMC interface and the solder alloy. Loading with higher shear component tends to result in more cohesive failure of the solder alloy near the solder/IMC interface. Under pure shear loading, failure is almost always cohesive within the solder alloy near the solder/IMC interface.

Implementation of a Mesoscopic Mechanical Model for the Shear Fracture Process Analysis of Masonry

2005 ◽  
Vol 297-300 ◽  
pp. 1025-1031 ◽  
Author(s):  
Shu Hong Wang ◽  
Chun An Tang ◽  
Juan Xia Zhang ◽  
Wan Cheng Zhu
Keyword(s):  
Mechanical Model ◽  
Damage Mechanics ◽  
Shear Fracture ◽  
Process Analysis ◽  
Pure Shear ◽  
Failure Process ◽  
Shear Loading ◽  
Short Paper ◽  
Masonry Material ◽  
Cracking Process

This short paper will present a two-dimensional (2D) model of masonry material. This mesoscopic mechanical model is suitable to simulate the behavior of masonry. Considering the heterogeneity of masonry material, based on the damage mechanics and elastic-brittle theory, the new developed Material Failure Process Analysis (MFPA2D) system was brought out to simulate the cracking process of masonry, which was considered as a three-phase composite of the block phase, the mortar phase and the block-mortar interfaces. The crack propagation processes simulated with this model shows good agreement with those of experimental observations. It has been found that the shear fracture of masonry observed at the macroscopic level is predominantly caused by tensile damage at the mesoscopic level. Some brittle materials are so weak in tension relative to shear that tensile rather than shear fractures are generated in pure shear loading.

scholarly journals Microalgal biomass as renewable biofiller in natural rubber compounds

2021 ◽  
Author(s):  
Emanuela Bellinetto ◽  
Riccardo Ciapponi ◽  
Marco Contino ◽  
Claudia Marano ◽  
Stefano Turri
Keyword(s):  
Thermal Analysis ◽  
Carbon Black ◽  
Natural Rubber ◽  
Shear Fracture ◽  
Pure Shear ◽  
Rubber Matrix ◽  
Compression Moulding ◽  
Microalgal Biomass ◽  
Dynamic Mechanical ◽  
Rubber Compounds

AbstractMicroalgal biomasses, consisting of micronized Spirulina Platensis and its low protein fraction, were investigated in this work as possible renewable biofillers in natural rubber compounds, with the aim of replacing the commonly used carbon black. Natural rubber, in some cases blended with 10% of epoxidized natural rubber to improve the matrix-filler affinity, was compounded with 25, 35, 50 and 75 phr of each biomass. Compounds with 25, 35 and 50 phr of carbon black N990 were also prepared as benchmarks. After compounding, vulcanization times were determined by dynamic mechanical analysis. Rubbers were vulcanized by compression moulding and characterized by means of morphological analysis (scanning electron microscopy), thermal analysis (thermogravimetric analysis, dynamic mechanical thermal analysis) and mechanical tests (tensile tests, strain induced crystallization detection by X-ray diffraction, pure shear fracture tests). Microalgal biomass turned out to be homogeneously dispersed in natural rubber matrix and the materials obtained required lower curing times compared to carbon black compounds. It was found that, up to 50 phr, Spirulina has the ability to increase rubber tensile strength and modulus, acting similarly to N990, while decreasing rubber thermal stability and fracture toughness.

Fracture Characterisation by Butterfly-Tests and Damage Modelling of Advanced High Strength Steels

2021 ◽  
Vol 883 ◽  
pp. 294-302
Author(s):  
Bernd Arno Behrens ◽  
Kai Brunotte ◽  
Hendrik Wester ◽  
Matthäus Dykiert
Keyword(s):  
Stress State ◽  
Shear Fracture ◽  
Pure Shear ◽  
Testing Machine ◽  
High Strength Steels ◽  
High Strength ◽  
Fracture Initiation ◽  
Forming Limit ◽  
Advanced High Strength Steels ◽  
Damage Models

Advanced High Strength Steels (AHSS) are widely used in today's automotive structures for lightweight design purposes. FE simulation is commonly used for the design of forming processes in automotive industry. Therefore, besides the description of the plastic flow behaviour, also the definition of forming limits in order to efficiently exploit the forming potential of a material is required. AHSS are prone for crack appearances without prior indication by thinning, like exemplary shear fracture on tight radii and edge-fracture, which can not be predicted by conventional Forming Limit Curve (FLC). Stress based damage models are able to do this. However, the parameterisation of such models has not yet been standardised. In this study a butterfly specimen geometry, which was developed at the Institute for Forming Technology and Machines (IFUM), was used for a stress state dependent fracture characterisation. The fracture behaviour of two AHSS, CP800 and DP1000, at varied stress states between pure shear and uniaxial loading was characterised by an experimental-numerical approach. For variation of the stress state, the specimen orientation relative to the force direction of the uniaxial testing machine was orientated at different angles. In this way, the relevant displacement until fracture initiation was determined experimentally. Subsequently, the experimental tests have been numerically reproduced giving information about the strain and stress evolution in the crack impact area of the specimen for the experimentally identified fracture initiation. With the help of this testing procedure, two different stress-based damage models, Modified Mohr-Coulomb (MMC) and CrachFEM, were parameterised and compared.

Compressive Behavior at Ambient Temperature of ZK60-xDy Magnesium Alloys

2016 ◽  
Vol 849 ◽  
pp. 128-133
Author(s):  
Zheng Hua Huang ◽  
Wen Jun Qi ◽  
Jing Xu
Keyword(s):  
Ambient Temperature ◽  
Shear Fracture ◽  
Pure Shear ◽  
Extrusion Direction ◽  
Axial Direction ◽  
Compressive Property ◽  
Compressive Behavior ◽  
Specimen Dimension ◽  
Zk60 Alloy ◽  
Specimen Orientation

Effects of the compressive rate, specimen dimension, specimen orientation and microstructure on the compressive property at ambient temperature of extruded ZK60-xDy alloy rods were investigated. The results show that the specimen dimension, specimen orientation and microstructure except the compressive rate play a significant role on the compressive property. The compressive strength σbc increased significantly by the improving amplitude of 65~110 MPa with increasing the height/diameter ratio h/φ of the cylindrical compressive specimen from 0.5 to 1, however it was not enhanced further as h/φ increased to 2. With increasing the value of h/φ, the yield stage on the compressive curve was strengthened gradually, and meanwhile the compressive macro-fracture changed from the inverted "V" type to pure shear fracture with an angle of 45°. Compared with the specimen whose axial direction was parallel to the transverse direction, σbc was enhanced by the improving amplitude of 60~120 MPa for the specimen whose axial direction was parallel to the extrusion direction. When small amount of Dy (0.31%) was added into ZK60 alloy, σbc was increased from 500 MPa to 540 MPa. However, it slightly decreased to 515 MPa again when the Dy content increased to 4.32%.

scholarly journals Compressive Behavior of (Cu0.47Zr0.45Al0.08)98Dy2 Bulk Metallic Glass at Different Strain Rates

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5828
Author(s):  
Yu-Ting Wang ◽  
Xu-Dong Zu ◽  
Xiang-Kui Liu ◽  
Zheng-Xiang Huang ◽  
Peng-Gang Jin ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Strain Rate ◽  
Yield Stress ◽  
Bulk Metallic Glass ◽  
Shear Fracture ◽  
Pure Shear ◽  
Shear Mode ◽  
Strain Rates ◽  
Fracture Behaviors ◽  
Compressive Tests

The mechanical properties of (Cu0.47Zr0.45Al0.08)98Dy2 bulk metallic glass (BMG) were characterized under various strain rates by quasi-static and dynamic compressive tests. In the quasi-static compressive tests, the yield stress of (Cu0.47Zr0.45Al0.08)98Dy2 BMG increased from 1234 MPa to 1844 MPa when the strain rate was increased from 0.001 s−1 to 0.01 s−1, and the yield stress decreased to 1430 MPa at the strain rate of 0.1 s−1. In the dynamic compressive tests, when the strain rate increased from 1550 s−1 to 2990 s−1, the yield stress of (Cu0.47Zr0.45Al0.08)98Dy2 BMG first decreased from 1508 MPa to 1404 MPa, and then increased to 1593 MPa. The fracture behaviors of (Cu0.47Zr0.45Al0.08)98Dy2 BMG were studied by using scanning electron microscopy to examine the fracture surface. Fracture occurred in the pure shear mode with strain rates below 2100 s−1, whereas shear fracture and normal fracture occurred simultaneously under strain rates of 2650 s−1 and 2990 s−1.

The velocity of shear fracture

1964 ◽  
Vol 54 (1) ◽  
pp. 369-376
Author(s):  
L. Mansinha
Keyword(s):  
Shear Stress ◽  
Compressive Stress ◽  
Poisson’S Ratio ◽  
Shear Fracture ◽  
Pure Shear ◽  
Maximum Velocity ◽  
Poisson's Ratio ◽  
Tensile Fracture ◽  
Transverse Waves ◽  
Isotropic Elastic Medium

abstract The maximum velocity of fracture in an homogeneous isotropic elastic medium under pure shear stress and with an added compressive stress is computed by an extension of Yoffe's method. The maximum velocity of shear fracture is smaller than the velocity of transverse waves in the medium. It increases as Poisson's ratio increases and decreases as the compressive stress increases. The maximum velocity of pure shear fracture is higher than the velocity of pure tensile fracture in the same medium. For a medium with Poisson's ratio of 0.25 the former is 0.775 and the latter is 0.631 of the transverse wave velocity.

Preparation of Graphene Nanolayers through Surfactant-assisted Pure Shear Milling Method

2019 ◽  
Vol 1 (1) ◽  
pp. 28-33
Author(s):  
Asghar Kazemzadeh ◽  
Mohammad Ali Meshkat ◽  
Hooman Kazemzadeh ◽  
Mostafa Moradi ◽  
Reza Bahrami ◽  
...  
Keyword(s):  
Pure Shear ◽  
Milling Method ◽  
Graphene Nanolayers ◽  
Surfactant Assisted

An octahedral stress-based fracture criterion for hyperelastic materials

2020 ◽  
pp. 095440622097213
Author(s):  
A Hamdi ◽  
A Boulenouar ◽  
N Benseddiq
Keyword(s):  
Pure Shear ◽  
Thermoplastic Elastomer ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Principal Stresses ◽  
Hyperelastic Materials ◽  
Biaxial Tests ◽  
Set Up ◽  
Loading Modes ◽  
Styrene Butadiene

No unified stress-based criterion exists, in the literature, for predicting the rupture of hyperelastic materials subjected to mutiaxial loading paths. This paper aims to establish a generalized rupture criterion under plane stress loading for elastomers. First, the experimental set up, at breaking, including various loading modes, is briefly described and commented. It consists of uniaxial tests, biaxial tests and pure shear tests, performed on different rubbers. The used vulcanizate and thermoplastic rubber materials are a Natural Rubber (NR), a Styrene Butadiene Rubber (SBR), a Polyurethane (PU) and a Thermoplastic elastomer (TPE). Then, we have investigated a new theoretical approach, based upon the principal stresses, to establish a failure criterion under quasi-static loadings. Thus, we have proposed a new analytical model expressed as a function of octahedral stresses. Quite good agreement is highlighted when comparing the ultimate stresses, at break, between the experimental data and the prediction of the proposed criteria using our rubber-like materials.

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