Search results

Variability in composite materials properties Andy Vanaerschot1,a , Stepan Lomov2,b , David Moens1,c and Dirk Vandepitte1,d∗ 1KU Leuven Dept. of Mechanical Engineering, Kasteelpark Arenberg 41 - box 2449 - Belgium 2KU Leuven Dept. of Materials Engineering, Kasteelpark Arenberg 44 - box 2450 - Belgium aandy.vanaerschot@kuleuven.be, bstepan.lomov@mtm.kuleuven.be, cdavid.moens@kuleuven.be, ddirk.vandepitte@kuleuven.be Keywords: composite materials, anisotropic properties, orthotropic properties, material identification, variability, correlation length Abstract.
Fibre reinforcement geometry together with material properties of fibre and matrix determine homogenised material properties.
The factors which affect variability are also listed, and the effect of variability on material parameters is mentioned as well.
The face sheets have either isotropic in-plane properties (e.g. aluminum foils) or orthotropic properties (e.g. a glass or carbon fibre weave).
Especially with thin foil honeycomb cores, the area of the wetted surfaces between the cell wall or the face sheet and the adhesive in relation to the volume of adhesive is uncertain, affecting the strength of the bond.

Currently, pre-strain and micro-alloying would be the two methods commonly used to improve the mechanical properties of Al-Mg alloys.
Liu et al. [14] found that Ce would also refine the grain size and improve the mechanical properties of Al alloy.
The refinement effect of rare earth elements would be the main factors for the ultimate tensile strength of Al alloys and the second phases would be harmful factor to the mechanical properties due to the net distribution around the boundary.
The distribution of second phases could explain the mechanical properties of the alloy.
Seidman, Microstructure and mechanical properties of a 5754 aluminum alloy modified by Sc and Zr additions, Mater.

The microstructure and mechanical properties of the four spring steels with different Si content treated by Q-I-Q-T process were studied by metallographic microscope, MTS, impact testing machine and X-ray stress analyzer.
When Si content reaches 2.1%, the comprehensive properties of 60Si2CrVA spring steel is the best.
Results and discussion Mechanical properties of four spring steels with different Si content.
The changes in the mechanical properties of four spring steels with different Si content are depicted in Figure 1.
The relevant literature reported that there are many factors will affect the stability of the retained austenite, such as the volume fraction of retained austenite, carbon content in retained austenite, the size and morphology of the retained austenite, distribution position, deformation temperature, stress state, technology for heating processing and so on, among them, the biggest impacts on the stability of retained austenite are the first three[11,12,13].

Burek et al. [21] investigated the mechanical properties of Bi by relating to its microstructure.
Skudnov et al. [22] explained the hardness of SnBi solder alloy was affected by two factors, namely phase interface density (ρ) and fraction of Bi.
In the same study, the thermal properties, mechanical properties, and microstructure evolution of SnxBi (x = 0, 10, 17, 20, 30, 40, 50, and 58 wt.%) was looked at.
E.: Wetting behavior of Sn–Ag–Cu and Sn–Bi–X alloys: Insights into factors affecting cooling rate.
M.: Mechanical properties of bismuth at different temperature and strain rates.

Because of the differences in physical properties, the aeronautic PMMA for porthole may easily craze, crack and even explode in flight.
In this paper, the operating conditions for porthole were analyzed and testing methods of PMMA’s thermo-physical properties were studied considering the two main factors, temperature and pressure, which affects porthole’s operating life.
However, airplane is inevitably affected by various severe environmental factors in flight, in which crack and even explosion may appear for the aeronautic PMMA.
In China, Guo Weiguo[3] studied the deformation and failure behavior of MDYB-3 oriented PMMA glass under different loading conditions, and pointed out MD-3’s thermodynamic properties were strongly affected by strain rate and temperature.
Aeronautic PMMA possesses excellent optic, intensity, heat-resisting, age-resisting and UV-resisting properties.

Current emerged as the most significant factor affecting the microhardness along with powder mixed in the dielectric and electrode material.
The results were analyzed using analysis of variance (ANOVA) for identifying the significant factors affecting the performance.
Current followed by powder suspended in dielectric were identified as significant factors affecting microhardness of the non-deposited region.
Electrode material and current are the other two factors that significantly affect the microhardness.
The presence of copper has marginal effect on improving the mechanical properties of ferrite phase.

Some preliminary test of post-welding heat treatments (PWHTs) have been investigated to homogenize as far as possible the microstructure and the mechanical properties across the seams.
Their corrosion and mechanical resistance properties at high temperature are due to the excellent stability of their microstructure.
The stability of microstructure depends on two main factors: i) the low misfit of lattice parameter between γ and γ’ and ii) the reduced interface energy (20-30 mJ/m2) [3-6].
Therefore, superficial defects and cracks may occur, leading to progressive degradation of mechanical properties.
Feng, Effects of post-weld heat treatment on microstructure and mechanical properties of TLP bonded Inconel718 superalloy.

The physical and mechanical properties of the PALF are given in Table 1.
Physical and Mechanical properties of PALF.
Besides that, crystallization, branching, frequency of the applied voltage, and temperature also affect these properties [15].
Mechanical properties of pineapple leaf fiber reinforced polyester composites.
Dynamic mechanical properties of pineapple leaf fiber polyester composites.

Nanomaterials have gained increased attention because of their improvement of mechanical properties of concrete.
Table (4) Measured mechanical properties of the control specimens Group Beam No.
These results clearly indicate that the dominant factors in mechanical enhancement are the percentage and type of nanoparticles, the hybrid addition of nanosilica and nanotitanium had a more substantial effect in mechanical enhancement of high strength concrete.
Table (4) summarises the experimental results of mechanical properties of the control specimens.
This different existed because of the distinct mechanical properties of nanomaterials, which gave the beams different flexural behavior.

Anisotropic Mechanical Properties of Pure Magnesium Analyzed by In situ Nanoindentation Jiří Bočan1,a,*, Jan Maňák1,b and Aleš Jäger1,c 1Laboratory of Nanomaterials and Interfaces, Institute of Physics of the AS CR, v.v.i., Na Slovance 1999/2, 182 21 Praha 8, Czech Republic abocanj@fzu.cz, bmanak@fzu.cz, cjager@fzu.cz Keywords: In situ nanoindentation, EBSD, mechanical properties anisotropy, pure magnesium Abstract: In this work, correlation between nanomechanical properties and crystallographic orientation of grains in 99.9 % magnesium is presented.
Introduction During past two decades, nanoindentation proved to be a convenient technique for measurement of mechanical properties of various materials at the micrometer and sub-micrometer length scales.
However, one of the main disadvantages is the hcp structure which causes their anisotropic properties.
The effects affecting the obtained results were also discussed.
Brown, The effect of crystallographic orientation on the mechanical properties of titanium, J.