硬质合金刀具在刀具总值中的变化

分析了21世纪初日本及西方其它国家的硬质合金刀具销售值(或产值)占刀具总销售的比例,及几种发展迅速的新兴硬质合金刀具品种。     

在线张力仪在长丝后加工中的应用

介绍了HDS-EX2加弹机中在线张力仪的基本功能和基本指标,并从原丝质量、机械设备及丝道不正三方面原因分析了一些常见的张力波动图,论述了在线张力仪在长丝后加工中质量监测的重要作用。     

Experimental determination of torsion and shear properties of sandwich panels and laminated composites by the plate twist test

A recently developed sandwich plate twist test is employed here for determination of the transverse shear modulus of the core and twist stiffness (D₆₆) of a sandwich panel consisting of a soft (H45 PVC foam) core and glass/vinylester face sheets. The shear modulus of the H45 PVC foam core extracted from the twist test was in good agreement with shear modulus obtained from ASTM plate shear testing of the foam core. D₆₆ values obtained from the sandwich twist test were in good agreement with predictions from classical laminated plate theory. In addition, the twist test was used to determine the in-plane shear modulus of glass/vinylester laminates isolated and as face sheets in sandwich panels with a stiff (plywood) core. The in-plane shear modulus of the face sheets, isolated and as part of a sandwich panel, was in good agreement with shear modulus determined using the Iosipescu shear test. The results point to the potential of the twist test to determine both in-plane and out-of-plane shear moduli of the constituents of a sandwich structure, as well as D₆₆.     

Aeroelastic stability predictions for a MW‐sized blade

Classical aeroelastic flutter instability historically has not been a driving issue in wind turbine design. In fact, rarely has this issue even been addressed in the past. Commensurately, among the wind turbines that have been built, rarely has classical flutter ever been observed. However, with the advent of larger turbines fitted with relatively softer blades, classical flutter may become a more important design consideration. In addition, innovative blade designs involving the use of aeroelastic tailoring, wherein the blade twists as it bends under the action of aerodynamic loads to shed load resulting from wind turbulence, may increase the blade's proclivity for flutter. With these considerations in mind it is prudent to revisit aeroelastic stability issues for a MW‐sized blade with and without aeroelastic tailoring. Focusing on aeroelastic stability associated with the shed wake from an individual blade turning in still air, the frequency domain technique developed by Theodorsen for predicting classical flutter in fixed wing aircraft has been adapted for use with a rotor blade. Results indicate that the predicted flutter speed of a MW‐sized blade is slightly greater than twice the operational speed of the rotor. When a moderate amount of aeroelastic tailoring is added to the blade, a modest decrease (12%) in the flutter speed is predicted. By comparison, for a smaller rotor with relatively stiff blades the predicted flutter speed is approximately six times the operating speed. When frequently used approximations to Theodorsen's method are implemented, drastic underpredictions result, which, while conservative, may adversely impact blade design. These underpredictions are also evident when this MW‐sized blade is analysed using time domain methods. Published in 2004 by John Wiley & Sons, Ltd.     

90°阶梯扭波导设计

应用跳变理论及二项式匹配原理,分析、研制了90°阶梯扭波导,相对于扭管波导,90°阶梯扭波导具有结构紧凑、体积小巧等优点,特别对在要求小巧的空间结构中转换极化方向是非常有利的。利用HFSS电磁场仿真软件对该波导进行了仿真计算,通过调整阶梯扭转角及阶梯长度,实际制作了1个90°阶梯扭波导并对其进行了测试,电性能参数优良,在相对带宽40%的频率范围内实现了驻波VSWR〈1.05,损耗｜α｜〈0.04。计算结果与实测结果基本一致,表明该实现方法是正确和有效的。     

麻花钻前刀面的研究

麻花钻前刀面的螺旋槽形状的不同,直接影响着主刃的切削性能和加工刀具的轴向轮廓,结合麻花钻特有的几何特性,推导了一般情况下的麻花钻端截面方程和铣刀轮廓方程,并借助LabVIEW的数学工具包编写了相应的程序,在Pro/E中进行实体验证与理论完全吻合,为麻花钻精确建模和加工刀具的轮廓设计提供了一种新的方法。     

纯棉高支强捻色织绉布的开发

详细介绍了纯棉高支强捻色织绉布产品的规格,经纬纱的选择,捻度的选择及织布的技术要点。认为在设计和生产过程中,纬纱捻度的选择较为重要。     

钢绳机上的崩头撸股自动停车装置

设计了一种用于钢绳生产的自动停车装置，使用它操作者能及时发现故障，立即处理，当出现崩头、撸股时钢绳机的有效停车率达９５％以上。     

渐速膛线身管内弹丸贴膛一般运动的研究

建立了非对称弹丸在挠性渐速膛线身管内作贴膛一般运动的微分方程组，求解了对称弹丸在渐速膛线理想身管内的贴膛运动规律。     

弹力竹节织物在喷气织机上的生产实践

针对弹力竹节织物织造过程中的技术难点,提出了增加纱线捻度、合理上浆工艺、减小喷气压力、增大主喷嘴和止纱销的角度等技术措施.