摘要：In the International Thermonuclear Experimental Reactor（ITER） project,the feeders are one of the most important and critical *** convey the power supply and the coolant for the central solenoid（CS） magnet,6 sets of CS feeders are employed,which consist mainly of an in-cryostat feeder（ICF）,a cryostat feed-through（CFT）,an S-bend box（SBB）,and a coil terminal box（CTB）.To compensate the displacements of the internal components of the CS feeders during operation,sliding cold mass supports consisting of a sled plate,a cylindrical support,a thermal shield,and an external ring are *** check the strength of the developed cold mass supports of the CS3U feeder,electromagnetic analysis of the two superconducting busbars is performed by using the CATIA V5 and ANSYS codes based on parametric ***, the thermal-structural coupling analysis is performed based on the obtained results,except for the stress concentration,and the *** intensity is lower than the allowable stress of the selected *** is found that the conceptual design of the cold mass support can satisfy the required functions under the worst case of normal working *** these performed activities will provide a firm technical basis for the engineering design and development of cold mass supports.

摘要：The numerical simulation on drawing process of automotive B-pillar was carried out on AutoForm software,and dangerous forming areas were *** processing parameters,such as the layout of drawbeads,blank holding force and the shape of blank,were adjusted and optimized according to the simulation *** indicate that the quality defects can be forecast and removed,which improves the stability of forming *** cost of design is decreased and the research cycle is *** is proved that the drawing process and die design of B-pillar forming are feasible in actual production.

摘要：In design of flexure mechanism, diminishing the parasitic-motion is a key point to improve the accuracy. However, most of existing topics concentrate on improving the accuracy of linear-motion flexure mechanisms via compensating the parasitic error, but few research the multi-dimensional flexure mechanisms. A general design principle and method for high-precision flexure mechanisms based on the parasitic-motion compensation is presented, and the proposed method can compensate the parasitic rotation in company with translation, or the parasitic translation in company with rotation, or both. The crucial step for the method is that the parasitic motion of a flexure mechanism is formulated and evaluated in terms of its compliance. The overall compliance matrix of a general flexure mechanism is formulated by using screw theory firstly, then the criteria for the parasitic motions is introduced by analyzing the characteristics of the resultant compliance matrix as well as with aid of the concept of instantaneous rotation center. Subsequently, a compliance-based compensation approach for reducing parasitic-motion is addressed as the most important part. The design principles and procedure are further discussed to help with improving the accuracy of flexure mechanisms, and case studies are provided to illustrate this method. Finally, an analytical verification is provided to demonstrate that the symmetry design philosophy widely used in flexure design can effectively improve accuracy in terms of the proposed method. The proposed compensation method can be well used to diminish the parasitic-motion of multi-dimensional flexure mechanisms.

摘要：This study investigates the redesign of a structural system with the matrix modification. The inertia congruence transformation is adopted to find the latent roots of a dynamic stiffness matrix, and a method for determining its eigenvalue is proposed. The characteristics of the latent vector for a known latent root and a method for computing it are studied. The mode shapes of the redesigned structure must be differently handled based on whether the structure exhibits persistent or non-persistent natural frequencies.

摘要：To support modular fixture assembly design in virtual environment,a multi-view based modular fixture virtual assembly model is *** of squeezing all assembly related information into a single model,three complementary views of assembly model,element information,function and structure,and assembly relationship are proposed to be *** first view contains the detailed element information,while the other two explicitly capture the hierarchical function relationships and mating relationships *** views are complementary in the sense that each view only contains a specific aspect of assembly related information while together they include required assembly related *** proposed assembly model is specialized to accommodate the features of modular fixture virtual assembly design and applied in our developed prototype system.

摘要：The new mechanism of drum-shaped gear with ring-involute teeth is presented to implement dimensional transmission for the stairlift. The structure of the gear and rack in this actuating mechanism is designed, and then its inherent radius of turn and modulus selection have been studied. In order to make the mechanism move steadily, the drive guide is proposed. After using the dynamics simulation software ADAMS to analyze the 3D model, this kind of mechanism is confirmed to be able to implement dimensional track. The useful method and basis would be provided for the optimization design of the mechanism.

摘要：Currently,osteochondral(OC)tissue engineering has become a potential treatment strategy in repairing chondral lesions and early osteoarthritis due to the limited self-healing ability of ***,it is still challenging to ensure the integrity,physiological function and regeneration ability of stratified OC scaffolds in clinical *** OC scaffolds are attractive to overcome the above problems because of their similar biological and mechanical properties with native OC *** a consequence,the researches on biomimetic design to achieve the tissue function of each layer,and additive manufacture(AM)to accomplish composition switch and ultrastructure of personalized OC scaffolds have made a remarkable *** this review,the design methods of biomaterial and structure as well as computer-aided design,and performance prediction of biopolymer-based OC scaffolds are presented;then,the characteristics and limitations of AM technologies and the integrated manufacture schemes in OC tissue engineering are summarized;finally,the novel biomaterials and techniques and the inevitable trends of multifunctional bio-manufacturing system are discussed for further optimizing production of tissue engineering OC scaffolds.

摘要：The high pressure waves generated due to muzzle blast flow of tank gun during firing is a critical issue to examine. The impulsive noise from the gun has various negative effects such as damage of human bodies, damage of structures, creating an environmental, social problem and also military problems such as exposure of location of troops. This high pressure impulsive sound, generated during the blast flow, was studied and attenuated. An axisymmetric computational domain was constructed by employing Spalart Allmaras turbulence model. Approximately 90% of pressure and 20 dB of sound level are reduced due to the use of the three baffle silencer at the muzzle end of the gun barrel, in comparison with the tank gun without silencer. Also, the sound pressure level at different points in the ambient region shows the same attenuation in results. This study will be helpful to understand the blast wave characteristics and also to get a good idea to design silencer for large caliber weapon system.

摘要：This paper presents the development of a normal adjustment cell (NAC) in aero-robotic drilling to improve the quality of vertical drilling, by using an intelligent double-eccentric disk normal adjustment mechanism (2-EDNA), a spherical plain bearing and a floating compress module with sensors. After the surface normal vector is calculated based on the laser sensors' feedback, the 2-EDNA concept is conceived specifically to address the deviation of the spindle from the surface normal at the drilling point. Following the angle calculation, depending on the actual initial position, two precise eccentric disks (PEDs) with an identical eccentric radius are used to rotate with the appropriate angles using two high-resolution DC servomotors. The two PEDs will carry the spindle to coincide with the surface normal, keeping the vertex of the drill bit still to avoid repeated adjustment and position compensation. A series of experiments was conducted on an aeronautical drilling robot platform with a precise NAC. The effect of normal adjustment on bore diameter, drilling force, burr size, drilling heat, and tool wear was analyzed. The results validate that using the NAC in robotic drilling results in greatly improved vertical drilling quality and is attainable in terms of intelligence and accuracy. (C) 2015 The Authors. Production and hosting by Elsevier Ltd. on behalf of Chinese Society of Aeronautics and Astronautics.

摘要：A new contact model of traveling wave ultrasonic motor （TWUSM） with a visco-elastic stator frictional layer was presented. In this model, the initial boundaries were revised, and the rotor revolution speed could he calculated iteratively. This model was compared with compliant slider and rigid stator model. The results of motor characteristics simulations showed that the motors based on this model would gain bigger stall torque. Then the friction and wear characteristics of two models were analyzed. The motors based on this model had lower coefficient of friction and better wear resistance.