The Improvement of the Fracture Behaviour of Polybutyleneterephthalate Modified by Highly Dispersed Metals

2002 ◽  
Vol 10 (3) ◽  
pp. 249-256 ◽  
Author(s):  
S. Ozden ◽  
T.A. Borukayev ◽  
N.I. Mashukov ◽  
A.K. Mikitayev
Keyword(s):  
Mechanical Properties ◽  
Failure Mechanism ◽  
Mechanical Behaviour ◽  
Structural Defect ◽  
Fracture Behaviour ◽  
Crystalline Size ◽  
Entanglement Density ◽  
Amorphous Phases ◽  
Highly Dispersed

The failure mechanism of polybutyleneterephthalate (PBT) was improved by the addition of highly dispersed Fe/FeO to the polymer. The mechanical behaviour of the materials under impact was investigated. It was shown that the addition of Fe/FeO stabilised the failure mechanism of PBT and improved its mechanical properties. Increased interphases between crystalline and amorphous phases, decreased crystalline size, increased network entanglement density and decreased critical structural defect length were responsible for these improvements.

scholarly journals Mechanical behaviour of Ostrich’s eggshell at compression

2013 ◽  
Vol 61 (3) ◽  
pp. 729-734 ◽  
Author(s):  
Šárka Nedomová ◽  
Jaroslav Buchar ◽  
Jana Strnková
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behaviour ◽  
Fracture Behaviour ◽  
Rupture Force ◽  
Compression Force ◽  
Static Stiffness ◽  
Static Compression ◽  
Deformation And Fracture ◽  
Rupture Energy ◽  
Chicken Eggs

The deformation and fracture behaviour of Ostrich’s eggs at the static compression has been investigated. The mechanical properties of egg to compression were determined in terms of average rupture force, specific deformation and rupture energy along X and Z axes. Exact description of the eggshell counter shape has been used for the verification of a common accepted theory of the compression of bodies of convex form. The eggshell strength seems to be an unique function of the static stiffness. The greatest amount of force required to break the eggs was required when eggs were loaded along the X axis and the least compression force was required along the Z axis. The specific deformation and rupture energy required for the eggs tested was lower along the X axis than the Z axis. The highest measure of firmness in the eggs tested was found to be along their X axis. Young’s modulus of the elasticity, E, has been also evaluated. Its value is independent on the direction of the egg compression. The value of E is approximately two times higher that of the chicken eggs.

scholarly journals Evolution of the viscoelastic properties of painting stratigraphies: a moisture weathering and nanoindentation approach

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Mathilde Tiennot ◽  
Davide Iannuzzi ◽  
Erma Hermens
Keyword(s):  
Mechanical Properties ◽  
Relative Humidity ◽  
Cultural Heritage ◽  
Mechanical Behaviour ◽  
Viscoelastic Properties ◽  
Viscoelastic Behaviour ◽  
Storage And Loss Moduli ◽  
Heritage Studies ◽  
Paint Films ◽  
The Impact

AbstractIn this investigation on the mechanical behaviour of paint films, we use a new ferrule-top nanoindentation protocol developed for cultural heritage studies to examine the impact of repeated relative humidity variations on the viscoelastic behaviour of paint films and their mechanical properties in different paint stratigraphies through the changes in their storage and loss moduli. We show that the moisture weathering impact on the micromechanics varies for each of these pigment-oil systems. Data from the nanoindentation protocol provide new insights into the evolution of the viscoelastic properties dsue to the impact of moisture weathering on paint films.

scholarly journals Mesoscale Modelling of Concretes Subjected to Triaxial Loadings: Mechanical Properties and Fracture Behaviour

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1099
Author(s):  
Qingqing Chen ◽  
Yuhang Zhang ◽  
Tingting Zhao ◽  
Zhiyong Wang ◽  
Zhihua Wang
Keyword(s):  
Mechanical Properties ◽  
Tensile Stress ◽  
Failure Criterion ◽  
Mesoscale Model ◽  
Fracture Behaviour ◽  
Descent Method ◽  
Triaxial Stress ◽  
Gradient Descent Method ◽  
Stress States ◽  
Shear Failures

The mechanical properties and fracture behaviour of concretes under different triaxial stress states were investigated based on a 3D mesoscale model. The quasistatic triaxial loadings, namely, compression–compression–compression (C–C–C), compression–tension–tension (C–T–T) and compression–compression–tension (C–C–T), were simulated using an implicit solver. The mesoscopic modelling with good robustness gave reliable and detailed damage evolution processes under different triaxial stress states. The lateral tensile stress significantly influenced the multiaxial mechanical behaviour of the concretes, accelerating the concrete failure. With low lateral pressures or tensile stress, axial cleavage was the main failure mode of the specimens. Furthermore, the concretes presented shear failures under medium lateral pressures. The concretes experienced a transition from brittle fracture to plastic failure under high lateral pressures. The Ottosen parameters were modified by the gradient descent method and then the failure criterion of the concretes in the principal stress space was given. The failure criterion could describe the strength characteristics of concrete materials well by being fitted with experimental data under different triaxial stress states.

scholarly journals Effect of the mechanical properties and mode loading on the mechanical behaviour of weldment: a numerical analysis

2013 ◽  
Vol 16 (4) ◽  
pp. 853-859 ◽  
Author(s):  
Meddah Hadj Miloud ◽  
Ould chikh Bahri ◽  
Benhamena Ali ◽  
Benguediab Mohamed ◽  
Bouchouicha Benattou
Keyword(s):  
Mechanical Properties ◽  
Numerical Analysis ◽  
Mechanical Behaviour

scholarly journals Atomistic investigation into the mechanical behaviour of crystalline and amorphous TiO2 nanotubes

RSC Advances ◽  
2016 ◽  
Vol 6 (33) ◽  
pp. 28121-28129 ◽  
Author(s):  
Yanan Xu ◽  
Mingchao Wang ◽  
Ning Hu ◽  
John Bell ◽  
Cheng Yan
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Titanium Dioxide ◽  
Molecular Dynamics Simulations ◽  
Mechanical Behaviour ◽  
Tio2 Nanotubes ◽  
Amorphous Tio2 ◽  
Dynamics Simulations

The mechanical properties of titanium dioxide (TiO2) nanotubes are studied based on molecular dynamics simulations.

Microstructure, Hardness, and Wear Resistance of Powder-Injection-Molded Products of Fe-Based Metamorphic Powders

2007 ◽  
Vol 26-28 ◽  
pp. 355-358
Author(s):  
Chang Kyu Kim ◽  
Chang Young Son ◽  
Dae Jin Ha ◽  
Tae Sik Yoon ◽  
Sung Hak Lee
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Wear Resistance ◽  
Injection Molding ◽  
Powder Injection Molding ◽  
Powder Injection ◽  
Thermally Stable ◽  
Austenitic Matrix ◽  
Amorphous Phases ◽  
Injection Molded

Powder injection molding (PIM) process was applied to Fe-based metamorphic alloy powders, and microstructure, hardness, and wear resistance of the PIM products were analyzed and compared with those of conventional PIM stainless steel products. When Fe-based metamorphic powders were injection-molded and then sintered at 1200 oC, completely densified products with almost no pores were obtained. They contained 34 vol.% of (Cr,Fe)2B borides dispersed in the austenitic matrix without amorphous phases. Since these (Cr,Fe)2B borides were very hard and thermally stable, hardness, and wear resistance of the PIM products of Fe-based metamorphic powders were twice as high as those of conventional PIM stainless steel products. Such property improvement suggested new applicability of the PIM products of Fe-based metamorphic powders to structures and parts requiring excellent mechanical properties.

The tensile behaviour of biaxial and triaxial braided fabrics

2016 ◽  
Vol 47 (8) ◽  
pp. 2184-2204 ◽  
Author(s):  
Duchamp Boris ◽  
Legrand Xavier ◽  
Soulat Damien
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Mechanical Behaviour ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Tensile Behaviour ◽  
Linear Mass ◽  
Double Peak ◽  
Specific Behaviour ◽  
Braiding Angle

The tensile behaviour of braid reinforcement is classically described by the behaviour of composite elaborated from these reinforcements. Few studies concern the tensile behaviour of braided fabrics. In this paper biaxial and triaxial braids are manufactured on a braiding loom. The evolution of key parameters as linear mass and braiding angle in function of process parameters is presented. Braid reinforcements are characterized in uniaxial tensile. The mechanical behaviour is analysed and compared in function of the braiding angle, but also different kinds of braid are considered. A specific behaviour called “double-peak” is identified for triaxial braids which have a higher braiding angle. The evolution of the braiding angle measured during tensile tests gives a comprehension on the mechanical behaviour of dry braids. Associated with this experimental study, an analytical model is also proposed, to predict mechanical properties of braid reinforcements.

scholarly journals Study on Mechanical Properties and Failure Mechanism of Axial Braided C/C Composite

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Chunguang Wang ◽  
Weiping Tian ◽  
Min Tang
Keyword(s):  
Mechanical Properties ◽  
Failure Mechanism ◽  
Fiber Bundle ◽  
Strain Curve ◽  
Axial Direction ◽  
Radial Compression ◽  
Compression Sample ◽  
Transverse Fiber ◽  
Failure Morphology ◽  
Axial Fracture

In order to study the mechanical properties and failure mechanism of the axial braided C/C composites, the microscopic and macroscopic mechanical properties of the composite were investigated. In view of the size effect of the samples, the properties of the samples with different thickness were tested. The strain during loading was measured by optical method, and the failure morphology was observed by SEM. The changing characteristics of stress-strain curve were analyzed, and the failure characteristics of materials and failure mechanism under various loads were obtained. It was found that brittle fracture was observed during the tensile process of axial braided C/C composites, and the main failure forms were fiber rod pulling and partial fiber rod breaking in the axial direction. Radial failure was mainly in the form of fiber bundle fracture and crack stratification propagation. When compressed, the material exhibited pseudoplastic characteristics. The radial compression sample was cut along a 45-degree bevel. The axial compression curve was in the form of double fold, the axial fiber rod was unstable, and the transverse fiber bundle was cut. During in-plane shearing, the axial fracture was brittle and the fiber rod was cut. The radial direction showed the fracture and pulling of the fiber bundle, and the material had the characteristics of pseudoplasticity. The research methods and results in this paper could provide important references for the optimization and rational application of C/C composite materials.

scholarly journals Numerical Simulation of the Fracture Behaviour of High-Performance Fibre Reinforced Concrete by Using a Cohesive-Crack-Based Inverse Analysis

2021 ◽  
Author(s):  
Alejandro Enfedaque ◽  
Marcos G. Alberti ◽  
Jaime C. Gálvez ◽  
Pedro Cabanas
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Inverse Analysis ◽  
High Performance ◽  
Fracture Behaviour ◽  
Constitutive Models ◽  
Cohesive Crack ◽  
Fibre Reinforced Concrete ◽  
Steel Fibres ◽  
Structural Applications

Fibre reinforced concrete (FRC) has become an alternative for structural applications due its outstanding mechanical properties. The appearance of new types of fibres and the fibre cocktails that can be configured mixing them has created FRC that clearly exceed the minimum mechanical properties required in the standards. Consequently, in order to take full advantage of the contribution of the fibres in construction projects, it is of great interest to have constitutive models that simulate the behaviour of the materials. This study aimed to simulate the fracture behaviour of five types of FRC, three with steel hooked fibres, one with a combination of two types of steel fibres and one with a combination of polyolefin fibres and two types of steel fibres, by means of an inverse analysis based on the cohesive crack approach. The results of the numerical simulations defined the softening functions of each FRC formulation and have pointed out the synergies that are created through use of fibre cocktails. The information obtained might suppose a remarkable advance for designers using high-performance FRC in structural elements.

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