Search results

There are lots of factors that frequently cause damage on aircraft wings and wing panels, which often remains invisible on the surface.
Present design of aircrafts uses large safety factors to account for possible damage, which leads to cost and weight increase.
Vibration-based methods are based on the fact that the introduction of damage in a structure changes its physical properties which in turn leads to changes in its vibration response.
This stage normally contains transformations that have some clustering properties and can reduce the dimensionality of the initial data vectors.
Van Overmeire: Mechanical Systems and Signal Processing, vol. 16(4), (2002), p.637

Numerous investigations are ongoing in searching for suitable Mg alloy systems with superior properties.
Grain refinement and texture randomization during thermomechanical processing (TMP) are the two most important factors to be considered to improve the formability as well as the mechanical properties of wrought magnesium alloys [2].
In many other alloys, precipitates have been used to control these factors.
Park, The microstructure, tensile properties, and creep behavior of AZ91, AS52 and TAS652 alloy, Journal of Alloys and Compounds, 493 (2010) 502-506
Niu, The microstructure, tensile properties, and creep behavior of as-cast Mg-(1-10)%Sn alloys, Journal of Alloys and Compounds, 440 (2007) 122-126

Based on the experimental results, some researchers studied the variation of the structure dynamic parameters related to the material properties in non-machining and machining states, such as natural frequencies, mode shapes and damping ratios, which should be considered in the modeling of the virtual machine tool[4-7].
Based on the structure, component material properties and movement features of the centerless grinding machine tool, the kinematic model of the feed system, dynamic characteristics of the grinding system and control technologies are combined for the development of the virtual centerless grinding machine.
Dynamic Study of the Grinding System Based on the Material Properties.
Among the mechanical system of the machine, the components which affect the process directly and remarkably contain the grinding wheelhead, control wheelhead and workrest assembly.
The material removal process and grindings forces are influenced by a lot of factors, such as the geometry and material properties of the workpiece and tool, machine characteristics, control techniques and machining parameters, etc.

Especially, the study and analysis are made for some main factors, such as formation of magnetic field, design of permanent magnetic circuit, shape of magnetic pole, preparation and property of magnetic abrasive powder.
Furthermore, with the NC machine tool, the finishing of complicated curved surface was carried out, the technological parameters affecting the processing quality are optimized, in which permanent magnet takes the place of electromagnet.
The manual method does not conform to the demands of modernized manufacture because of its low productivity and high labor intensity, and also because the machining quality often relies on the subjective factors out of operators.
Thus, magnetic abrasive powder with high performance is one of the essential factors to handle both machining efficiency and quality.
The analysis for how magnetic flux density and magnetic pole’s rotational velocity is affecting the machining result respectively is given in next section.

It is the key to ensure the safety of power transmission tower, people life and property.
The public facilities and people's life and property pose a serious hazard [1, 2].
Influenced by mining, uneven settlement of the building consists of two parts: one part is settlement of the building with the subsidence of the surface integrally, which depends on the mining technology, mineral occurrence conditions and factors such as surface geological conditions; the other part is due to the foundation soil disturbance, compressibility changes, thus in the process of surface integral sinks, foundation and ground relative subsidence.
So if mined-out area appears at the bottom of the tower foundation, it is likely to affect transmission tower, even damage, this is very dangerous.
As far as possible avoiding influence within the scope of 6m from the building foundations, it is a key to ensure the power transmission tower safe, and people life and property from loss.

The web height is the controlling factor in the optimization design .After determining other three parameters, the web height controls the maximum deflection.
Combining the advantage of good mechanical properties, easy and efficient construction, light weight, high durability to corrosion, we develop a kind of FRP sluice gate, and plan to apply it to certain engineering.
Consider the influence of single parameter on the maximum deflection and volume fraction function,then drew the influence curve,and in this way, primary factors will be found.
If the number of webs be increased, the maximum deflection value will be largely affected before the number reaching the cross point and the affection will be little after the number of webs exceeding the cross point both to the maximum deflection value and the volume fraction.
So web height controlling is a main factor in the process of FRP strobe optimizing.

Pointed to character of flexible support of cave dwelling on prestressed anchor for geotechnical engineering, rheological mechanics was used to analyze support effects,and a new viso-elasto-plastic rheological model was built with locked minimum load formula abtained.Such is the property that bonding soil,surrounding soil,bolts and arc surface were studied.And the finite difference method(FLAC3D) with C++ and inline FISH program were applied to analyze stress, anchor,plastic state,shear strain rate and displacement distribution.Based on calculated results and investigation on spot, plenty of key parameters on whole bonged and prestressed bolt were studied.
The numerical calculation is coincident with testing factors.So the theory basis is provided for effective support engineering.
(1) Vertical displacement and anchor load after reinforcement a.after one month b.after two month c.after six month Fig.4 Contour of vertical displacement(Unit:m) The calculated results show in Fig.4 on rheological displacement after reinforcement.For surface layer restriction on arc, the maximum displacement is around 2.6cm after six month and deformation velocity will tend to convergenc compared to acceleration firstly,which will not affect on the stability,the reinforcement measurement is effective.
The results that have been calculated by numerical method FLAC3D with FISH and C++ program show the abtained formula and numerical calculation with rheological are coincident with investigation and testing factors on spot.
stability analysis of pile-slope systems”,Computer and Geotechnics,issue 32,2005,304-315,2005 [4] Iizuka A, Ohta H, “A determination procedure of input parameters in elasto-viscoplastic finite element analysis”, Soil and Foundation,Vol.27,issue 3,71-87,1987 [5] Ostermayer H , Scheele F, “Research on Gound Anchors in Noncohesive Soil”,Proceeding of the 9th International Conference on Soil Mechanics and Foundation Engineering.Tokyo:the Japanese Society of Soil Mechanics Engineering, 96-103,1997 [6] JIA Jin-qing, ZHENG Wei-feng, “Study and application of flexible retaining method with prestressed anchor”,Chinese Journal of Geotechnical Engineering, Vol.27,issue 11,1257-1261,2005(in Chinese) [7] JIA Jin-qing , ZHENG Wei-feng ,CHEN Guo-zhou, “Numerical analysis of prestressed anchor flexible retaining method”,Chinese Journal of Rock Mechanics and Engineering, Vol.24,issue 21, 3978-3982,2005 (in Chinese) [8] WANG ZY,XU J,LI Y P,et al, “Rheological numerical simulation for thermo- hydro-mechanical

Houtian Hu [4] is based on the field test, analyzed the influence factors of rockfall movement, such as size, shape and slope conditions etc.
According to the domestic and foreign research data, such as Shunchuan Wu [5], based on the orthogonal test to study the factors affecting the motion characteristics.
(5) Where, VEXIT for the Rolling Stones to leave this section of the final slope surface speed; V0 for the rockfall cut side slope along the current direction of the initial velocity; S for the rockfall on the slope of the sliding distance of this paragraph; g is the gravity acceleration; k is a factor[7].
The case study Engineering situation Within the scope of the rockfall disease treatment engineering of some Railway Bureau, in order to solve the existing railway on the simple and quick, safe and effective construction of shed structure, put forward the light shed structure (shown in Fig.2) .The mechanical parameters of material properties of light shed structure is shown in Table 1.
Material properties Component E(Pa) ρ(kg/m3) Yield Strength(Pa) μ rockfall 3.25E+10 2600 - - main cable 2.06E+11 7850 1.55E+09 0.3 wire 2.06E+11 7850 1.55E+09 0.3 spring damping bar 2.06E+11 7850 1.90E+08 0.3 The calculation model of impact This paper uses the general explicit dynamic analysis design of the light shed structure of the program ANSYS/LS-DYNA for numerical simulation of rockfall dynamic impact process.

It was demonstrated that biochar was part of the black carbon continuum with variable properties due to the net result of production (e.g., feedstock and pyrolysis conditions) and postproduction factors (storage or activation).
But carbon black had inert surface properties which gave poor dispersion performance.
Therefore, compared with the HDPE/CB, the mechanical properties and ultraviolet (UV) resistance of HDPE/HDPE-g-CB were significantly improved, positively influencing the expected life span of pipelines.
[37] He XL, Cai YQ, Wang QT, Qi X, Guo R, Tang Y, Liu BP., Improvement of Mechanical Properties and Ultraviolet Resistance of Polyethylene Pipe Materials Using High Density Polyethylene Matrix Grafted Carbon Black, J.
Mustafi., Effect of Modified Carbon Black on the Properties of Natural Rubber Vulcanizate, J.

As for suspension, its rheological properties are affected by the particle size significantly, determining the freezing behavior of suspension and then the following sintered porous microstructure.
It is also well know that the particle size is strongly relative with the sintering behavior of matrix, which greatly influences the mechanical properties of the sintering porous ceramics.
The mechanical properties of sintering porous ceramics were characterized. 2.
The above two factors make the nano-sized particles easier to be engulfed in the frozen ice front.
Oda, Physical properties of slip casting of high pure Al2O3 slurry using porous Al2O3 glass mold, J.