基于纤维弯曲伸长模式的Ｚ向钢针针尖形态优化

分析了整体穿刺过程中纤维弯曲伸长机理，建立了钢针的力学模型，分别讨论了作用在针尖上的最大弯曲正应力、最大剪切应力以及穿刺阻力与针尖半径和针尖长度之间的关系，然后根据获得的结果对钢针针尖的形状进行了优化。     

正交叠层机织布整体穿刺工艺的纤维弯曲伸长机理

分析了正交叠层机织布整体穿刺工艺机织布与钢针的相互作用，提出并建立了纤维的弯曲伸长及伸长断裂模式，讨论了影响纤维弯曲伸长的结构参数。通过理论分析和试验结果说明，绕针弯曲伸长断裂是Z向钢针直径和Z向距比值X的函数，为减少整体穿刺的纤维伸长断裂应选取较小的X比值。     

非英语专业学生英语听说能力的培养——一份整体语言教学指导下的课堂教学模式实验报告

整体语言教学作为一种语言教学思想,近年来被一些国家引入第二语言/外语教学中。笔者以“整体语言教学和英语听说能力培养的关系”为题进行了为期一年的教学实验,具体探讨了整体语言教学在大学英语课堂教学中的实施。     

Study on the Bending Properties of Woven Fabrics and Its Yarns

A theoretical analysis on the two extreme cases of yarn bending rigidity as well as the relationship between them is proposed. The significant influence of fiber-to-fiber interaction on yarn bending rigidity is revealed. Experimental observation on the relationship between fabric/yarn bending property and fiber fineness, yam structure, fabric structure is given as well. Three problems are discussed and the following conclusion is thus obtained. There exists, similar to a rigid engineering rod, a linear relationship between yarn bending rigidity and the square of yarn fineness (expressed as yarn count in tex), but the increasing speed is much lower. Yarn bending rigidity in the fabric also to a great extent depends on the fabric density and yam twist factor, and so on. Fabric's bending hysteresis primarily depends on its bending rigidity.     

机织物及其纱线弯曲性能的实验研究

应用织物及纱线弯曲刚度的理论研究成果，借助实验手段考察研究了织物及其中纱线的弯曲性能与纤维线密度，纱线结构及织物结构的关系。获得如下主要结论：纱线的弯曲刚度与纱线线密度的平方线性相关，二者的单相关系数在0．70以上；织物中纱线的弯曲刚度还与织物紧度、纱线捻系数，织造和染整加工中的张力等因素有关，织物的弯曲滞后量主要取决于织物的弯曲刚度。     

Study on Bending of Woven Fabrics Using Linear Viscoelasticity Theory

The bending behavior of woven fabrics under low curva-ture conditions has been analyzed by linear viscoelastictheory.The fabric is assumed to behave viscoelasticallyand to be subjected to frictional restraints in bending de-formation.The frictional restraint is considered to beproportional to the curvature and can be described by africtional moment.A model has been constructed by astandard three-element solid model and a paralleledfrictional sliding element.The equations of the model fora cyclic curvature variation are derived.A set of param-eters of the equations for each fabric has been obtainedexperimentally.Predictions of the bending rigidity andhysteresis for wool,cashmere,wool/polyester blended,polyester and cotton fabrics are made,displaying verygood agreement with the experimental observations.     

Bending Hysteresis of Twill Woven Fabrics in Various Directions

This paper investigates the bending hysteresis of twill woven fabrics in various directions. In this research, existing models for the prediction of bending rigidity of woven fabrics are applied to bending hysteresis. Wide range of cotton twill woven fabrics is examined by comparing the theoretical data and experimental results. The results of this paper indicated that Peirce's, Shinohara et al's and Cooper's models can be applied to the prediction of bending hysteresis of twill woven fabrics. Besides, the results also show that ratio V, introduced by Cooper, of a cotton twill fabric is found to have the range between 0.8 and 1.4. The general shape of the polar diagram of bending hysteresis along the weft direction is spreading outwards with the increase in ratio V from the range 0.8 to 1. However, the general shape of bending hysteresis will collapse around the weft direction when ratio V is increased from 1 and 1.4.     

储煤筒仓滑升模板优化施工方案

介绍了古交发电厂储煤筒仓的施工部署，从滑升模板设计、机具加工及组装、滑模装置的组装、滑模施工的过程和方法等方面论述了储煤筒仓滑升模板优化施工方案．并提出了施工质量控制措施。     

无缝钢管穿孔中顶头温度的实验研究

无缝钢管的穿孔过程是一个热加工过程 ,顶头的温度分布对于其寿命至关重要。应用热电偶埋入顶头的测量办法对顶头在生产过程的温度分布进行了实测。初步得到其温度的分布状况 ,为顶头的热处理提供依据     

基于双重弯曲度积的图像拐点检测

针对拐点处与非拐点处的弯曲度值差别小的问题,文中提出了一种基于双重弯曲度积的图像拐点检测算法,通过第一重弯曲度与第二重弯曲度的乘积扩大拐点处与非拐点处的弯曲度值的差别,并对数字图像进行拐点检测实验.结果表明,该算法不仅简单有效,而且具有较高的稳定性和准确性,能够解决实际的图像拐点检测问题.     

基于向量式有限元法的风力发电机组一体化仿真分析

大型风电机组为强非线性刚柔耦合的周期时变多体系统,传统有限元方法不能解决叶片转动过程中由于刚体位移而导致的刚度矩阵奇异问题,向量式有限元法可有效考虑叶片的几何非线性和大变形运动、塔架的弹性变形、气动载荷等因素.基于MATLAB平台编制空间梁系结构求解程序,选取悬臂梁受端部集中动荷载和欧拉梁绕定轴转动两个典型算例验证程序的正确性.建立包含机舱、轮毂、叶片和塔架在内的风电机组一体化仿真分析模型,根据机组静止状态下自由振动响应,用模态参数识别方法提取了机组的自振频率,计算结果与传统有限元法吻合.采用谐波叠加法和本征正交分解法相结合的方式,运用B样条曲面插值策略,模拟生成风电机组在正常运行状态下的风速时程.采用向量式有限元法对正常运行状态下的风电机组进行风振响应分析,较好地反映了重力对叶片内力周期性变化的影响以及叶片与塔架的共同作用.     

不锈钢管材弯曲成形回弹预测模型研究

为提高管材弯曲成形回弹预测精度,对回弹预测模型构建进行了研究.在1Cr18Ni9Ti不锈钢管材拉伸实验的基础上,提出并建立了分段非线性σ-ε模型,进而利用弹塑性变形理论构建了基于σ-ε关系的回弹预测模型,推导了回弹近似计算公式,并且对回弹影响因素进行了分析研究.实验结果表明,回弹预测结果与实验数据吻合较好,验证了理论分析的正确性和模型的有效性.     

钢管结构法兰连接节点抗弯承载性能的试验研究

研究了钢管结构法兰连接节点的抗弯承载性能.通过试验方法,采用螺栓应变测量装置,对含4种基本形式的法兰连接节点的试件进行四点弯加载试验,考察了在节点受弯过程中螺栓和法兰板的受力特性.试验得到了其屈服荷载与极限荷载,并且与相应的有限元分析结果吻合良好.试验结果表明,法兰连接节点的受拉区存在明显的撬力作用,刚性法兰连接节点的...