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Search Results: 1 - 10 of 36430 matches for " 晏冬秀 "
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蜂窝夹层修理结构的弯曲性能试验分析
郭霞,关志东,刘遂,孔娇月,,乔柳平
复合材料学报 , 2013,
Abstract: 采用四点弯加载方式研究分析了含损伤蜂窝夹层修理结构的弯曲性能,该夹层结构由碳纤维增强的聚合物面板和蜂窝芯子组成。进一步分析了挖补斜度、挖补方式、损伤程度、修理设备和修理材料对修理板弯曲性能的影响。研究表明,修理板的破坏模式可分为补片边缘折断、补片中面折断和胶层破坏三种,相同破坏模式修理板的名义弯曲强度相近,其中前两种破坏模式修理板的名义弯曲强度与完好板相近,而第三种破坏模式修理板的名义弯曲强度相对较低。所有修理板的名义弯曲强度恢复率基本处于95%以上,同时修理后抗弯刚度也满足修理准则。
纤维层内树脂流动的空气耦合超声无损检测
王占吉,刘玲,,何少刚
复合材料学报 , 2013,
Abstract: 采用空气耦合超声无损检测仪,对部分浸润预浸料中树脂沿纤维层厚度方向的浸渍流动进行了实时检测研究。首先将部分浸润预浸料放置在真空袋中,然后固定在扫描机构上,抽真空,考察在一个大气压作用下不同时刻树脂的浸润流动情况,通过C扫描图片实时、快速检测出树脂的浸润流动变化,并应用达西定律计算了碳纤维网架的渗透率。同时,将观察区域截取试样制备成金相分析试样,通过显微分析验证了C扫描图像分析的准确性。结果表明,空气耦合超声C扫描方法是检测预浸料中树脂沿纤维层厚度方向流动的一种快速和有效的方法。
复合材料蜂窝夹芯板挖补修理后的侧压性能
刘遂,关志东,郭霞,,刘卫平,孔娇月
科技导报 , 2013, DOI: 10.3981/j.issn.1000-7857.2013.07.003
Abstract: 对3种方法修理后复合材料蜂窝夹芯板的侧压性能进行实验研究.实验结果表明,不同修理方法均可有效地恢复试件的侧压强度,所有试件的侧压强度恢复率均在完好板强度的79%以上.其中,初始损伤最小的蜂窝夹芯板有最高的强度恢复率,此外非对称的修理设计会导致附加弯矩,从而对结构承载能力造成不利的影响.在实验基础上建立三维有限元模型对修理后蜂窝夹芯板的侧压性能进行研究,数值模型得到的结构刚度、极限载荷与破坏模式均与实验结果吻合良好,为复合材料蜂窝夹芯板的修理设计提供了可靠的数值方法.
搭接长度对复合材料单搭接胶接接头的影响
郭霞,关志东,刘遂,孔娇月,,乔柳平
科技导报 , 2013, DOI: 10.3981/j.issn.1000-7857.2013.07.005
Abstract: 针对复合材料单搭接接头的拉伸性能进行有限元建模,分析搭接长度对单搭接接头的应力分布和破坏模式的影响.结果表明当搭接长度在5~45mm变化时,最小剪切应力逐渐减小,当搭接长度大于20mm时,搭接长度对应力分布的影响减少;破坏载荷逐渐增大,当搭接长度大于20mm时,搭接长度对破坏载荷的影响减少;单搭接接头的破坏模式为胶层-复合材料界面的边缘发生部分损伤,导致胶层损伤,搭接长度的变化影响单搭接接头的损伤严重程度.
修理工艺对边缘封闭蜂窝夹层结构弯曲性能的影响
郭霞,关志东,刘遂,,刘卫平,孙凯
材料工程 , 2013, DOI: 10.3969/j.issn.1001-4381.2013.12.005
Abstract: 采用四点弯加载方式研究含损伤的边缘封闭蜂窝夹层结构修理后的弯曲性能,同时分析损伤直径、损伤类型和修理设备对修理板弯曲性能的影响。结果表明所有修理板的抗弯强度恢复率基本处于90%以上;热压罐固化比热补仪固化效果稍好;胶接质量好的前提下,损伤大小对修理效果没有影响,然而损伤越严重,对胶接质量的要求就越高;修理后结构中央的抗弯强度恢复率比结构边缘损伤的高。
一种模量双向变化的梯度复合平面梁的级数解
Series solutions of graded composite plane beam whose modulus varying in bi-directions

杨青,刘卫平,余木火,郑百林,,陈萍,贾丽杰,魏冉
- , 2016, DOI: 10.13801/j.cnki.fhclxb.20160324.002
Abstract: 3D打印技术的发展使复杂梯度结构的制造更加容易,有必要对复杂梯度问题的求解开展研究;目前,关于梁结构模量沿轴向或厚度方向梯度变化问题的研究已经较多,但对模量沿2个方向同时变化的研究较少。因此,通过复数形式傅里叶分解的方法对模量以指数形式沿厚度方向和轴向同时变化梯度平面复合梁问题进行了求解。首先,采用弹性力学半逆解法得到了问题的四阶变系数偏微分控制方程的通解;然后,利用级数展开,求解了对称载荷作用下该梁的特解;最后,通过与有限元结果进行对比,说明了级数解的正确性。结果表明:当梯度双向变化时,梁结构的应力分布和变形情况更加复杂,模量较高的位置应力较大,而模量较低的位置应力较小。提出的级数解还可推广至其他相关的梯度双向变化非均匀平面和半平面问题的研究。 As the development of 3D print technology makes the manufacturing of complex graded structures more easily, it is necessary to carrying out the investigations with respect to the solving for complex graded problems. Now, the investigations about the problems that the modulus of beam structures varying along the axial direction or thickness direction grade are already more, while the investigations about the modulus varying along two directions synchronously are less. Thus a graded composite plane beam with modulus changed in exponential form synchronously along thickness direction and axial direction was investigated by using Fourier decomposition in complex form. The general solutions for four-order differential governing equation with variable coefficients were solved firstly by using semi-inverse method of elasticity. Then, the particular solution of the beam subjected to symmetric load effects was derived by series expansions. Finally, the correctness of series solutions was verified by comparing with finite element results. The results show that when the gradient varying in bi-directions, the stress distribution and deformation situations of the beam structure become more complex, that the stress is larger at the region with higher modulus, while the stress is smaller at the region with lower modulus. The series solutions proposed could be also extended to the investigation of other relevant plane or semi-plane inhomogeneous problem with graded varying in bi-directions. 中国博士后科学基金(2015M581681);中国商飞中欧合作专项(SAMC14-JS-13-012)
蜂窝叶顶密封对透平级气动性能的影响研究
Effect of Honeycomb Shroud Seals on Aerodynamic Performance of Turbine Stages

,,李军
- , 2016, DOI: 10.7652/xjtuxb201604003
Abstract: 采用数值计算方法研究了蜂窝叶顶密封的几何尺寸对汽轮机高压缸两级内气动性能的影响,分析了蜂窝密封的几何参数,包括密封间隙、蜂窝孔深、蜂窝孔径对透平级气动性能的影响规律。研究结果表明:随着蜂窝密封间隙的增大,动叶下游静叶内二次流损失增加,透平级内总总等熵效率下降,密封内泄漏量近似线性增加;随着蜂窝孔深的增大,总总等熵效率先增大后基本趋于定值,泄漏量则随孔深的增大先减小然后趋于定值;蜂窝孔径对透平级气动性能的影响主要取决于孔内和密封出口的泄漏流场结构,随着蜂窝孔径的增大,总总等熵效率逐渐增大,泄漏量逐渐减小;蜂窝密封间隙的变化对主流流场的影响显著,蜂窝孔径的变化对主流流场的影响次之,而蜂窝孔深对主流流场的影响较弱。
Effects of honeycomb shroud seal dimensions on the aerodynamic performance of the steam turbine stages in the high??pressure cylinder are investigated by using a computational fluid dynamics method. Critical geometrical parameters, including the sealing clearance, hole??depth and hole??diameter, of the honeycomb seal are selected as research objectives to compute the performance of two turbine stages in a range of geometrical dimensions. Numerical results show that as the sealing clearance increases, the secondary loss downstream the rotor blade increases, the total??total isoentropic efficiency of turbine stages decreases and the leakage increases at an approximately linear rate. When the hole??depth increases, the total??total isoentropic efficiency increases at first and then keeps constant, while the leakage rate in the honeycomb seals decreases at first and then keeps constant. The effects of the honeycomb diameter on the leakage rate and stage efficiency are mainly determined by the flow field structure in the honeycomb cells and seal outlet region. As the hole??diameter increases, the total??total isoentropic efficiency increases while the leakage rate decreases. The variation of sealing clearance has a pronounced influence on the main flow field structure, while the change of hole??depth has less effect on the aerodynamic performance of turbine stages than that of sealing clearance. Among the three geometrical parameters, i.e. the sealing clearance, the hole??depth and the hole??diameter, the variation of hole??depth has weakest influence on the main flow field structures in the turbine stages
现代都市的心灵书写——评万宁小说集《麻将》
,杰雄
湖南工业大学学报(社会科学版) , 2013,
Abstract: 万宁的小说集《麻将》摒除了零度情感的叙事,以平等的视角和富有挑战性的心灵叙事,对现代都市作了深层书写。作者将笔触切入到都市人的心灵,淋漓尽致地描摹了都市人在欲望冲击下的婚恋病症以及他们在时代转型期心理的渴望与焦灼,从而使她的小说显现出厚重的历史感。
百色水利枢纽工程地下厂房锚杆无损检测分析
石林,秦莹,
武汉理工大学学报 , 2009,
Abstract: ?锚杆锚固质量及受力状态的检测目前大多停留在利用液压千斤顶进行破坏性拉拔试验的阶段,文中采用无损检测的方法对百色水利枢纽工程地下厂房主变岩锚杆锚固质量进行检测,应用小波分析对实测信号进行分解及重构,通过对重构前后的波形进行分析比较,研究表明采用文中所述方法对波形进行处理比原始波形能更有效地反映锚杆锚固状况,评价锚固质量。
采用2-自由度调节器结构的制动方向稳定性控制算法
蔚光,张卫,陈全世
控制理论与应用 , 2006, DOI: 10.7641/j.issn.1000-8152.2006.2.032
Abstract: 结合直接横摆力矩控制和主动前轮转向控制,设计了一种提高制动方向稳定性的复合控制系统.控制器采用2-自由度调节器结构,将前轮转向角视为输入,将作用于车身的外部侧向干扰力视为扰动,通过2-自由度调节器将转向跟随控制和抗扰控制分离,并对制动控制参数进行了优化.文章对有转向输入和路面突变情况下的控制器控制性能进行了仿真研究,并与无方向稳定控制的仿真结果进行了对比.仿真试验证实这种控制方法在提高车辆制动稳定性方面有良好的效果.
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