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the Human Engineering Analysis of the Racing Wheelchair Tianmin Guan 1, a, Lei Lei 2,b and Jiangbo Li3,c 1 School of Mechanical Engineering, Dalian Jiaotong University, Dalian 116028, China ag2000tm@yahoo.com.cn, bleileidalian@163.com, clijiangbo_ok@126.com Keywords: the Racing Wheelchair; the human engineering analysis; CATIA.
In order to improve the human engineering properties for the racing wheelchair, using the CATIA Human Engineering Analysis module, this paper established the human body 3-D model, analyzed the eligibility of the hold and the extend for the racing wheelchair, analyzed and evaluated the comfort of three typical sports postures of human body.
The Establishment of the Human Body Model The human body model is established based on human body parameters, it is an effective tool which describes morphological characteristics and mechanical properties of human body, it is also an indispensable auxiliary tool that can be used to research, analyze, evaluate, and test the man-machine system.
The reasonable human movement postures could reach the requirement of the human force, the unreasonable ones could cause fatigue, evoke occupational diseases and affect the match result during to energy over-consumption.
In this paper, the upper limb of the 3-D human body for the racing wheelchair model had three sports postures, which contained: initial posture when driving the wheelchair, one of Middle postures when driving the wheelchair, and open posture of both arms when leaving the wheelchair, these three postures we edited are shown in Fig.6. 1) Initial posture 2) Middle posture 3) Open posture Fig.6 Three sports posture edit Because the comfort is a subjective feeling, that is the comprehensive feeling of pain, fatigue, and force and so on, which is influenced by various physiological factors such as the joint angle, muscle tissue pressure and blood circulation block.

In order to accurately describe the physical properties of the material, this paper selects the Power Law material model of AdvantEdge FEM, including thermal softening , strain hardness , and the strain rate sensitivity .
The factors selected are the tool edge diameter d, the cutting speed Vc, the feed amount f, the drilling depth h, and the back taper Kt.
Four levels of these five factors were experimentally studied.
It can be seen from equations (8) and (12) that various factors have different effects on thrust force and torque.
In addition, the increase of the core thickness increment causes the thrust force to have the tendency to decrease; likewise, the degree to which torque is affected by various factors is similar to the thrust force.

According to this, one of the most important factors is environment pH.
It has strong effect on the kinetics of the anodic reaction and therefore properties of passive layer.
By decreasing pH the passive layer tends to dissolution and loses its protective properties [3].
It is known that the environment, the chemical composition, heat treatment and the microstructure can be affecting the pitting potential [19].
Frankel, Pitting corrosion of metals a review of the critical factors, J.

Nerve growth factor receptor (NGFR) p75 were applied to identify OECs by immunostaining.
OECs could secret various neurotrophic factors and signal molecules, such as brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), glia cell line-derived neurotrophic factor (GDNF) and NT-4/5 [4], which could imposed on the microenvironment.
The nanofibers orientation in SF tube affects the mechanical property of SF tube.
In order to get an intuitive and three-dimensional cell morphology, SEM was applied to observe the adhesion and spreading properties of OECs on different materials. samples were rinsed with PBS for three times and respectively fixed in 4% glutaraldehyde and 1% osmic acid for 1h.

In this paper, a honeycomb sandwich beam and a plate are studied to verify a method of determining the equivalent properties of these structures.
The specimen is mainly applied to aircraft interior sheet, so the mechanical properties is worse than that is used as the load-carrying structure in the aviation field.
So in the vibration transmission of the beam, there’s only one volume uncertain in Gcxz, Gcyz, ρf, which affects the transmission curve(Gcxz in beam1 and Gcyz in beam2).
Therefore the category and amount of bond is an important factor in the process of honeycomb sandwich structure manufacture.
Research on Equivalent Models of the Mechanical Function for Aluminium Honeycomb Sandwich Panel.

Tturbulent field consist of different size eddy, the difference caused by eddy pulling between the largest and smallest sizes of which depends on specific flow property.
(10) Including: K is a function of physical property and oar model, when the type of agitator and mixing materials are determined, K is constant.
The size of aperture ratio directly relate to the velocity gradient flowing through fluid around between pores and blades, and thus affect the ratio between the local energy dispersion in the groove fluid and the main body energy dispersion, so this will affect the groove macro mixing process. 3.3.2 the aperture of opening pores When aperture ratio is constant, the diameter of pores must relate to the speed of orifice flowing, and also affect the speed of orifice flowing and the velocity gradient around surrounding fluid.
The kinetic energy of concurrent flow losses in the process of exchange, that makes the entrainment effect could not be completely played, affecting eddy diffusion.
Application of Fluorescent PIV and Digital Image Analysis to Measure Turbulence Properties of Solid-liquid Stirred Suspensions[J].

Meanwhile, we selected elastic-plastic mechanical model and incremental theory to analyze the problem. 1.1 Establishing heat source model Because the hot spread quickly in metal, highly concentrated heat source was used to transfer much more heat to workpiece in an instant and causes time-variation and unsteady characteristics during welding. we selected realistic model of normal heat considering materials’ physical properties changes with temperature[3].
Assuming the distribution of heat is Gaussian normal distribution function, then integrates the equation is: （1） （2） （3） Where: q—effective heat power, J/s； k—heat concentration factor,1/mm2； r—the distance between a point within the circle heat source and the center.
Therefore, judging from thermal expansion and contraction properties of the metal, different parts of the weldment will get different temperatures, and will lead to different thermal expansion.
However, the materials thermal expansion close to molten pool affected by mental around gets deeper than that away from weld seam, which will result in the materials In the weld and around subject to relatively large compressive stress.
Temperature Field of Thick Welding Process, Three-dimensional Finite Element Numerical Simulation of the Stress Field[J],Chinese Mechanical Engineering,2001,12(2):183~186

Introduction The tool–material interactions under machining conditions modify significantly the properties of metal near surface layers and subsequently their behavior and durability.
For long time, the appreciation of the surface integrity and the properties of the near surface layers affected by machining were based on experimental approaches combining a variety of techniques and methods of mechanical and physicochemical investigations [1-3].
These approaches are expensive and lead to more or less significant uncertainties of surface properties.
Nevertheless, numerical models are rarely used to predict the properties of machined surface for the case of aluminum alloys.
The created heat is transferred to chip, to tool and to workpiece in proportions depending on tool and material properties and cutting conditions.

High-temperature hot deformation is linked with dynamic recovery and recrystallization which affect the alloy structure and properties.
When optimizing hot processing of austenitic alloys, such factors should be taken into account as [3]: grain size, intermetallic phases and carbides precipitation processes and strain parameters.
Two of the above-mentioned factors are considered most important: austenite grain size and the course of recrystallization during hot deformation.
This is particularly important in creep-resisting steels and austenitic alloys, where grain refining has an advantageous influence on their mechanical properties and creep characteristics [2, 4].
The alloy deformed in the temperature range 1000÷1050 °C exhibited the properties characteristic of dynamically recrystallized structures.

Surgical strategies that have evolved to deal with tissue loss include organ transplantation from one individual to another, tissue transfer from a healthy site to an affected site in the same individual, and replace- ment of tissue function with mechanical devices.
As a biomaterial, ploy(lactic acid) (PLA) possesses good chemical and biological properties, such as good biocompatibility, bioresorbability, which offer PLA many biomedical and biotechnological applications[7].
Key factors seem to be its ability to bond bone minerals directly and to promote new bone formation by osteoconduction [9,10].
At the same time, we discussed the mechanism by which the different preparing conditions affected the performances of microsphere- based tissue engineered scaffolds.
PLA scaffolds with 0.3g β-tricalcium phosphate Mechanical properties.