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We performed electrical deformation experiments on the film actuator under different prestrain ratios. 2.3 Material characterization 2.3.1 Mechanical property The mechanical properties were carried out with a tensile machine (Shimadzu corporation, AUTOGRAPH AG-X) using dumbbell specimen.
Table 1 shows the mechanical and electrical properties of them.
The properties are summarized in Table 2.
This may come from the fact that the increase of the dielectric constant is smaller than the increase of Young’s moludus and dielectric loss factor.
Properties of actuators for the matrix and composites containing BaTiO3 of different volume fraction.

The stress concentration factor is calculated for a ply with modeling crack under the condition of different loads.
This material is utilized by the aviation, high speed railway industry due to its relative lightweight and high strength, as well as its excellent gap sensitivity and stress anti-rust property.
The stress distribution around crack and rivet joints were studied for high strength aluminum alloys by Lock-in thermography, and the stress concentration factors of crack structure component were calculated under the condition of different loads.
Fig.1 shows the structure and the finite element mesh of the high strength aluminum alloy ANSI 7071. the ANSI 7071 mechanical and thermal properties have been given, the Young's modulus E is 69GPa, the Poisson's ration v is 0.33, the special heat c is 890 J/(Kg℃), the thermal diffusion coefficient α is 23.5 m 2/s, and the density ρ is 27100 Kg/m 3 The amplitude of sinusoidal load is 5400N and the load modulation frequency is 1Hz.
Ft=4.4KN X Y a) Experimental results Ft=4.4KN X Y b) FEM results c) Comparison along X d) Comparison along Y Fig.6 Stress distribution of crack structure Ft=5.4KN Ft=8.4KN Ft=11.4KN Ft=15.4KN Ft=17.4KN e) Stress distribution of different loads It can be known that the stress concentration factor is not affected by load for given crack geometry shape under different loads, for this crack structure component of ANSI 7071 high strength aluminum alloy, the stress concentration factor Kt is about 2.0 from Fig.7.

The mechanical properties of cast alloys mainly depend on the weight fractions of alloying elements, applied heat treatments, microstructures, morphologies of the various phases constituting [1].
This is because the cooling rate of steel has a significant effect on the solidification microstructure which dominates the final mechanical properties of steels [2].
Table 1 Comparison of grain average size, the primary dendrite arm space and the secondary dendrite arm space under different cooling rates Fig.4 Optical photographs of Cu-Ni alloy solidified under different cooling conditions (a) Silica sand, (b) Graphite, (c) Low carbon steel It is well known that the solidification rate plays an important role in the refinement of metal structures, and it significantly affects the mechanical properties.
In Cu-Ni alloys, dendritic segregation is another important factor that influences mechanical behavior and workability.

An online surface defects detection system for step-axis Jili Lu 1,2,a, Mingxing Lin 1,b 1School of Mechanical Engineering, Shandong University, Jinan 250061, China 2School of Mechanical and Electronic Engineering, Zaozhuang University, Zaozhuang 277160, China a lujili168@163.com, b mxlin@sdu.edu.cn Keywords: Defects Detection, Median Filter, Gray Variation, Feature Extraction, Support Vector Machine (SVM) Abstract.
To ensure the real-time property, a fast axial surface defects inspection method is put forward, including improved median filtering to reduce noise, gray variation for fast judgment, the maximum variance method (OTSU) to select threshold automatically, contour features for feature extraction, mathematical morphology to detect defect targets, and finally, support vector machine (SVM) to classify and recognize the surface defects of ladder shaft.
All these defects may affect the product’s performance, cause deformation, impact efficiency, lower product life, some even lead to crack propagation, especially when rotating in high speed, they may have more destructive.
To ensure real-time property, improved median filtering [5] is employed to smooth image.
Based on the characteristics and factors of these defects, it is known that the defect area is large and appears in single piece generally, the outline is clear, but the gray distribution is concentrated between background and defects, and the contrast is not obvious.

Magnesium alloys have been received an attention for structural applications due to their low density compared to other alloys, and intensive studies have been focused for enhancing mechanical strength and surface protection as well.
At the same time, the surface properties of the magnesium alloys have shown one critical barrier for a practical application of the alloy, leading that a fair number of studies for the surface protection has been focused via many coating routines [1, 2].
The surface morphology of the wear test specimen indicates that the coating layer affected the wear properties of the AZ magnesium alloys.
It appears that the pack cementation coatings can improve the surface properties of the magnesium alloys.
It appears that the critical factor for the successful pack cementation coating process is attributed to the coating powder species and annealing temperature.

In this heat-affected zone (HAZ) significant changes in the microstructure and properties take place due to the transformations induced by the thermal cycles.The HAZ can be divided into several subzones, depending on the peak temperature that the material has experienced.
The reduction of carbon content is the main factor in improving weldability and toughness of the coarse-grained HAZ.
They affect the austenite to ferrite transformation, but in different ways.
The safe use of an engineering structure relies on each of its components possessing the necessary mechanical properties, the most important of these properties usually being strength and toughness. [1] Strength The strength values are closely related to the volume fraction of martensite in the microstructure.
(For example, refer to chapter 5 of reference No.[1]) Toughness Toughness is considered to be a much more critical property of the HAZ than strength.

Introduction Interest for using high-strength zirconium oxide ceramics for the fabrication of computer- manufactured full coverage crowns and bridge frameworks is growing in recent years, due to their improved mechanical properties in comparison to more conventional alumina or lithium disilicate- based ceramics [1].
The control group (A) underwent no mechanical surface treatment following sintering.
To avoid the influence of other factors, this study chose hand grinding as the single pretreatment to get the zirconia surface with similar structure.
In other words, we should all relevant economic factors that have a bearing on the state of the shear bond strength in clinic use.
Within the limitations of this study, multiple factors may influence the shear bond strength in clinic, such as the temperature, load and other mechanical or chemical factors in month [7].

Effect of reinforcements on the ultraprecision performance of SIC reinforced aluminium matrix composites Dazhen Wang1, a, Peifeng Feng2,b and Ling You3,c 1,2,3College of Mechanical Engineering, Jimei University, Xiamen 361021, China adazhenwang@163.com, bpffeng@163.com, cyouling85yoyo@163.com Keywords: aluminium matrix composite, ultraprecision machining, SiC reinforcements, deformation mechanism, surface roughness.
However, despite all these attractive properties, the commercial and industrial application of SiC reinforced aluminium composites is limited[6,7].
Table 1 Physical and mechanical properties of the specimens Experimental Materials Volume fraction of Reinforcements j [%] Density r [g.cm-3] Tensile Strength sb [MPa] Young’s Modulus E [GPa] Elongation percentage [%] SiCw/LD2 15 2.85 650 160.0 2.0 SiCw/LD2 25 2.88 660 165.0 1.7 SiCp/LD2 15 2.71 400 99.0 1.8 LD2 - 2.70 330 70 16.0 The Atom Force Microscope (AFM) is from American Digital Instruments Company, and the tapping mode and Si3N4 probe with a cone angle of 35° are used for examination.
The surface quality in the ultraprecision turning of aluminium composites with polycrystalloid diamond PCD tool is affected by a number of factors[17,18], which include tool types and their geometrical angles, cutting parameters, the mechanical properties of specimens and vibration of the lathe, etc.
Chan, C.F.Cheung: International Journal of Mechanical Sciences, 2001, Vol.43, pp 2047-2068.

These phase transformations have a detrimental effect on the fatigue properties of the welded structure, which is made worse by the presence of notch stress concentration and residual tensile stresses [3].
In order to improve fatigue properties of steel welded components, hammer peening may be performed [2].
In this work, those three factors have been studied in order to assess their respective influence. 2.
The analyses were performed in the longitudinal and transverse directions, in the weld toe (heat affected zone) or in the hammered zone of the plates.
Since in most cases the crack, which leads to mechanical failure initiates from the surface of the work piece, components with nano or ultra-fine grain superficial layers are expected to have improved fatigue properties because both fatigue crack initiation and propagation are inhibited by the presence of fine grains near the surface and coarse grains in the interior, respectively.

It is well know that the aging process is an effective way to improve conductivity and mechanical properties of 6xxx series alloys [8-13].
Results Effect of Aging Process on Properties of Aluminum Alloy Wires.
Therefore, in the temperature scope (150-190˚C) of this study, the β″-precipitate was considered as the major factors affecting tensile strength and resistivity.
Sun, Effect of heat treatment on Microstructure and mechanical properties of 6082/6063 alloys D, Chang Sha: Central South University. (2012)
Effect of aging on mechanical properties of 6063 Al-alloy using instrumented ball indentation technique J, Materials Science & Engineering A. 527 (6) (2009)1590-1594