15CrMoR＋Incoloy825复合板的焊接工艺

通过大量的焊接工艺试验、分析及工艺评定试验验证,确定了15CrMoR＋In—coloy825复合板焊接及在15CrMoR基体上堆焊Incoloy825复合层最佳的焊接工艺规范参数及焊接工艺方法。熔敷金属（包括堆焊金属）的力学性能、化学成分及复合层的耐腐蚀性能等各项技术指标均达到了设计要求。     

带有压力梯度的平板边界层转捩数值模拟

对零压力梯度和带有压力梯度的平板边界层转捩实验T3A,T3C1和T3C2进行了数值模拟,计算结果与实验值吻合的较好,并得出以下的结论:压力梯度的存在对转捩起始的位置有较大的影响;M-L转捩模型能比较准确地预测转捩的发生和发展过程,但M-L一方程转捩模型因为要根据经验选取转捩起始动量厚度雷诺数,所以在通用性上相对M-L二方程转捩模型要弱;使用M-L转捩模型计算过程中,根据湍流的性质选取进口粘性比有助于正确地预测转捩的发展过程.      

Supersonic flutter control and optimization of metamaterial plate

A metamaterial plate is designed by embedding a periodic array of local nonlinear resonators for its supersonic flutter control. Based on the von Karman large deformation theory and supersonic piston aerodynamic theory, the nonlinear aeroelastic equations of the metamaterial plate are obtained by using the Hamilton principle. The comparisons for aeroelastic behaviors of the metamaterial plate and pure plate show that the proposed metamaterial plate can lead to an enlarged flutter boundary and lower vibration amplitude. Furthermore, a parametric optimization strategy for local nonlinear resonators is proposed to improve the nonlinear flutter behaviors of the metamaterial plate, and a significant enhancement of passive control performance can be achieved through optimization design. The present study demonstrates that the design of the metamaterial plate can provide an effective approach and potential application for nonlinear flutter suppression of supersonic plate.     

压电网络板的振动控制原理与控制效果

在给出压电网络板机电耦合动力学方程的基础上对其进行求解,将压电网络板的响应表示为子模态压电系统响应的线性组合.通过分析压电网络板在脉冲激励下子模态压电系统的响应行为,揭示压电网络板可以通过两种途径控制自身振动.基于对传递函数的分析进一步得到子模态压电系统的最优电学参数;在此基础上研究了针对某一阶子模态压电系统设计最优电学参数时,各阶子模态压电系统的响应行为以及压电网络板的多模态控制效果.研究结果表明,压电网络板具有多模态控制效果,特别地,当对板的某一阶次的振动控制具有较高要求时,通过对最优电学参数进行设计,电感电阻并联型压电网络板可满足要求.     

热载荷蜂窝夹层板作用下固有频率预测与分析

针对热载荷作用下蜂窝夹层板固有频率变化的问题,分析了蜂窝夹层板在热载荷作用下的应力分布及固有频率,并根据应力分布预测了夹层板的固有频率变化,与仿真得到的频率变化一致。仿真结果表明:碳纤维蒙皮蜂窝夹层板在热载荷作用下的固有频率基本不变,且约束形式对频率变化的影响很小;铝合金蒙皮蜂窝夹层板在热载荷作用下时,约束形式对频率变化影响很大,当约束较少时频率基本保持不变,当约束较多时将引起结构固有频率大幅下降。     

KM8不锈钢板式热沉激光焊接工艺研究

热沉是空间环境模拟器的重要组成部分之一,用于在真空热试验中产生冷黑环境。我国目前正在研制的KM8空间环境模拟器和KM7A空间环境模拟器的热沉均采用不锈钢板式结构,而不锈钢板式热沉的焊接加工工艺是亟需解决的技术问题。文章介绍了在KM8不锈钢板式热沉激光焊接工艺研究中,采用不同的工艺参数焊接了不同厚度的搭接组合板试件后,对这些试件进行了力学拉伸试验和焊缝分析与检测,并根据检测结果确定了不同厚度板材组合的最佳搭接焊接工艺参数。这些工艺参数在后续的生产实践得到了有效验证。     

Experimental and numerical simulation of bird-strike performance of lattice-material-infilled curved plate

The anti-bird-strike performance of a lattice-material-infilled curved plate is investigated herein. Since automatically filling the curved structure by classical lattice material filling methods will cause a large number of manufacturing defects, a space-dependent lattice material filling method for the curved plate is firstly proposed in this paper Next, using a face-centered cubic lattice, a lattice-material-infilled test piece with a hollow ratio of 40.8% is built. The test pieces are manufactured via additive manufacturing using titanium alloy. In bird-strike experimental tests, the test pieces are crashed against gelatin birds at an impact velocity of 200 m/s. Dynamic strain gauges are used to record the crash history and the results are discussed. Furthermore, a numerical analysis to simulate the bird-strike experiment is performed. The results from the experimental tests and numerical simulation agree well. This work shows that the lattice-material-infilled curved plate yields promising bird-strike resistance. Therefore, lattice-infilled materials are feasible for protecting aerospace components against bird-strike as well as for reducing the component weight.     

多孔板水升华器试验研究

探索了多孔板的制造方法,设计了水结器试验单元件和试验装置;对不同的多孔板升华器进行了试验研究,试验重点研究了热流体入口温度和流量、多孔板物理参数、给水室压力及升华器放置情况对升华器性能的影响。试验结果证明文章提出的升华器基本的设计概念是可行的,并给出了关于水升华器进一步设计的一些有益的结论。     

钢质蜂窝夹芯板的研究进展

钢质蜂窝夹芯板具有质轻、比强度高、减震、耐冲击和节省材料等优点,是一种具有良好发展前途的夹芯板。     

Dynamic analysis of the composite laminated repaired perforated plates by using multi-patch IGA method

The bonded repair techniques seem to be the most frequent procedures in the aviation maintenance. The achieved composite repaired perforated thin-walled plate is a complex geometry with high numerical analysis cost. The NURBS-based Isogeometric Analysis (IGA) proposes a sensible and affordable tool to carry out such geometry analysis. In this context, a well-known technique is to divide the original geometry assembly into number of simple neighbors connected geometries. In the present study the free vibration analysis of the perforated plates repaired on one side with an external bonded composite laminated patch is investigated. A multi-patch geometry modeling approach is implemented in line with the first order shear deformation theory of plates. In order to hold the geometry integrity and uniformity, all the degrees of freedom between adjacent geometry patches are completely tied through implementing a Nitsche method. To show the effectiveness and accuracy of the developed formulation, some representative results are extracted and compared with those from literature. The effects of geometrical as well as material parameters including boundary condition, cutout shape, and repair layup on the dynamic response of the repaired perforated plates are then investigated.