Correlation of the maximum shear stress with micro-mechanisms of ductile fracture for metals with high strength-to-weight ratio

2018 ◽  
Vol 146-147 ◽  
pp. 583-601 ◽  
Author(s):  
Yanshan Lou ◽  
Jeong Whan Yoon ◽  
Hoon Huh ◽  
Qi Chao ◽  
Jung-Han Song
Keyword(s):  
Shear Stress ◽  
Ductile Fracture ◽  
Maximum Shear Stress ◽  
Weight Ratio ◽  
High Strength

Stretch Formability Behaviour of Glass Fibre Reinforced Nanoclay on Fiber Metal Laminated Composites

2018 ◽  
Vol 10 (2) ◽  
Author(s):  
K. Logesh ◽  
V.K Bupesh Raja ◽  
C. Krishnaraj
Keyword(s):  
Ductile Fracture ◽  
Epoxy Resin ◽  
Glass Fibre ◽  
Weight Ratio ◽  
High Strength ◽  
Core Material ◽  
Fibre Metal Laminates ◽  
Sem Image ◽  
Pull Out ◽  
Fibre Metal

Innovations and research in material processing have brought forward new and improvised materials that are applied in body panels of automobiles, aircraft cabins and railway wagons. These materials are used widely is because of their good mechanical properties and their high strength to weight ratio. In this paper Fibre Metal Laminates (FMLs) were added with organo modified montmorillonite (MMT) commonly known as nanoclay along with epoxy resin. The homogeneous dispersion of nanoclay in epoxy resin is accomplished by a hand stirrer dispersion method in ethanol. The FML material was processed by hand layup method. In this study the aluminium alloy 5052-H32 was used as a skin material and glass fibre (woven roving) used as core material which is bounded by epoxy with 5 wt.% nano clay (closet 30B). The fabricated sandwich material was cut by using water jet machine as per IS standards for testing. The fabricated material subjected to erichsen cupping test and was observed under Scanning Electron Microscope (SEM). The results from SEM image analysis indicated that the FML had fibre pull out and surface cracks were obtained in the skin material. Progressive loading resulted in ductile fracture which is absorbed in the specimen. Fibres came across brittle failure and the skin through ductile fracture. Non-uniform distribution of reinforcement is observed in the material, SEM micrographs revealed fibre cracks which were oriented in line to the direction of crack growth on the skin material. This study shows that these fibre metal laminates can be safely applied in automotive field.

A Stress-Based Model for Shear Ductile Fracture

2019 ◽  
Vol 794 ◽  
pp. 3-8
Author(s):  
Yan Shan Lou ◽  
Jeong Whan Yoon
Keyword(s):  
Shear Stress ◽  
Ductile Fracture ◽  
Fracture Stress ◽  
Maximum Shear Stress ◽  
Stress Triaxiality ◽  
Fracture Model ◽  
Deformation Effect ◽  
Lode Parameter ◽  
Fracture Locus ◽  
Lightweight Metals

A stress-based model is developed to describe shear ductile fracture of lightweight metals. The proposed function couples the effect of the maximum shear stress and the stress triaxiality on fracture limits of metals during plastic deformation. Effect of the maximum shear stress in the proposed fracture model is correlated with the influence of the Lode parameter on fracture limits. The proposed fracture model is applied to depict the fracture locus of AA2024-T351. The predicted fracture locus is compared with experimental results of the alloy. The comparison demonstrates that the proposed fracture model reasonably characterizes the fracture stress in various loading conditions of compression, shear and tension.

scholarly journals On the Influence of Fracture Criterion on Perforation of High-Strength Steel Plates Subjected to Armour Piercing Projectile

2015 ◽  
Vol 62 (2) ◽  
pp. 157-179 ◽  
Author(s):  
Djalel Eddine Tria ◽  
Radosław Trebinski
Keyword(s):  
Shear Stress ◽  
Fracture Criterion ◽  
Maximum Shear Stress ◽  
Equivalent Plastic Strain ◽  
Stress Triaxiality ◽  
High Strength ◽  
Steel Plates ◽  
Fracture Model ◽  
Simple Material ◽  
Shear Plugging

Abstract This paper presents a numerical investigation of fracture criterion influence on perforation of high-strength 30PM steel plates subjected to 7.62x51 mm Armour Piercing (AP) projectile. An evaluation of four ductile fracture models is performed to identify the most suitable fracture criterion. Included in the paper is the Modified Johnson-Cook (MJC) constitutive model coupled separately with one of these fracture criteria: the MJC fracture model, the Cockcroft-Latham (CL), the maximum shear stress and the constant failure strain models. A 3D explicit Lagrangian algorithm that includes both elements and particles, is used in this study to automatically convert distorted elements into meshless particles during the course of the computation. Numerical simulations are examined by comparing with the experimental results. The MJC fracture model formulated in the space of the stress triaxiality and the equivalent plastic strain to fracture were found capable of predicting the realistic fracture patterns and at the same time the correct projectile residual velocities. However, this study has shown that CL one parameter fracture criterion where only one simple material test is required for calibration is found to give good results as the MJC failure criterion. The maximum shear stress fracture criterion fails to capture the shear plugging failure and material fracture properties cannot be fully characterized with the constant fracture strain

Precipitation in Al-Li-Zr alloys

1992 ◽  
Vol 50 (1) ◽  
pp. 186-187
Author(s):  
D.M. Vanderwalker
Keyword(s):  
Fracture Toughness ◽  
Precipitation Hardening ◽  
Weight Ratio ◽  
High Strength ◽  
Transmission Electron ◽  
Water Quench ◽  
Aluminum Lithium ◽  
Aluminum Lithium Alloys ◽  
Lithium Alloys ◽  
Zr Alloys

Aluminum-lithium alloys have a low density and high strength to weight ratio. They are being developed for the aerospace industry.The high strength of Al-Li can be attributed to precipitation hardening. Unfortunately when aged, Al-Li aquires a low ductility and fracture toughness. The precipitate in Al-Li is part of a sequence SSSS → Al3Li → AlLi A description of the phases may be found in reference 1 . This paper is primarily concerned with the Al3Li phase. The addition of Zr to Al-Li is being explored to find the optimum in properties. Zirconium improves fracture toughness and inhibits recrystallization. This study is a comparision between two Al-Li-Zr alloys differing in Zr concentration.Al-2.99Li-0.17Zr(alloy A) and Al-2.99Li-0.67Zr (alloy B) were solutionized for one hour at 500oc followed by a water quench. The specimens were then aged at 150°C for 16 or 40 hours. The foils were punched into 3mm discs. The specimens were electropolished with a 1/3 nitric acid 2/3 methanol solution. The transmission electron microscopy was conducted on the JEM 200CX microscope.

TUNGUM ALLOY

Alloy Digest ◽  
2012 ◽  
Vol 61 (5) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Weight Ratio ◽  
High Strength ◽  
Fatigue Properties ◽  
Excellent Corrosion Resistance

Abstract Tungum alloy combines an unusually high strength-to-weight ratio, with ductility, excellent corrosion resistance, and good fatigue properties. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming. Filing Code: Cu-806. Producer or source: Tungum Ltd.

SANDVIK Ti-3Al-2.5V GRADE 9

Alloy Digest ◽  
1997 ◽  
Vol 46 (9) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Endurance Limit ◽  
Weight Ratio ◽  
High Strength ◽  
Strain Ratio ◽  
Bend Strength ◽  
Aerospace Applications ◽  
Excellent Corrosion Resistance ◽  
Titanium Aluminum ◽  
Fatigue Endurance

Abstract Sandvik Ti-3Al-2.5V Grade 9 titanium-aluminum alloy offers excellent corrosion resistance, especially to chloride media, and has a high strength-to-weight ratio, which is especially suitable for use in aerospace applications. Tubing can be produced having a CSR (contractile strain ratio) that enhances the fatigue endurance limit. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and bend strength as well as fatigue. It also includes information on corrosion resistance as well as forming, machining, and joining. Filing Code: TI-109. Producer or source: Sandvik.

DONEGAL DC-50

Alloy Digest ◽  
1954 ◽  
Vol 3 (8) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
Precipitation Hardening ◽  
Weight Ratio ◽  
High Strength ◽  
Heat Treating

Abstract Donegal DC-50 is a precipitation hardening stainless steel having high strength-weight ratio. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as casting, heat treating, machining, joining, and surface treatment. Filing Code: SS-17. Producer or source: Donegal Manufacturing Corporation.

scholarly journals Tribological characterisation of magnesium matrix nanocomposites: A review

2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110090
Author(s):  
Sudip Banerjee ◽  
Prasanta Sahoo ◽  
J Paulo Davim
Keyword(s):  
Weight Ratio ◽  
High Strength ◽  
Stir Casting ◽  
Tribological Behaviour ◽  
Magnesium Matrix ◽  
Friction Stir ◽  
Wear Friction ◽  
Melt Deposition ◽  
Mechanical And Tribological Characteristics ◽  
Matrix Nanocomposites

Magnesium matrix nanocomposites (Mg-MNCs) are high grade materials widely used in aerospace, electronics, biomedical and automotive sectors for high strength to weight ratio, excellent sustainability and superior mechanical and tribological characteristics. Basic properties of Mg-MNCs rely on type and amount of reinforcement and fabrication process. Current study reviews existing literatures to explore contribution of different parameters on tribological properties of Mg-MNCs. Effects of particle size and amount of different reinforcements like SiC, WC, Al2O3, TiB2, CNT, graphene nano platelets (GNP), graphite on tribological behaviour are discussed. Incorporation of nanoparticles generally enhances properties. Role of different fabrication processes like stir casting (SC), ultrasonic treatment casting (UST), disintegrated melt deposition (DMD), friction stir processing (FSP) on wear and friction behaviour of Mg-MNCs is also reviewed. Contributions of different tribological process parameters (sliding speed, load and sliding distance) on wear, friction and wear mechanism are also examined.

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