褶皱结构成形时的形状偏差计算

解决了褶皱结构成形时相邻的平行四边形平面元素之间连接区棱的修圆半径值预测问题。把毛坯模拟成薄板，定义了平行四边形平面元素的边界条件，采用能量法导出挠度和力函数的非线性微分方程组，利用积分－差分法实现其数值解，并提供计算结果和分析应力－应变场。采用的计算方法可用于研究毛坯的刚度参数和工艺参数对褶皱结构的形状影响。     

Development of the Technique for Calculating the Ejectors with Low Entrainment Ratios

This paper presents the results of an investigation of ejectors with the low entrainment ratio. A technique for calculating the ejectors with a curvilinear axis has been developed. Comparative studies of the performance characteristics of ejectors with the rectilinear axis of the mixing chamber and the curvilinear initial section of the mixing chamber are carried out.     

A study of Z-crimp structural parameters impact on strength under transverse compression and longitudinal shear

Results of exerimental studies for composite Z-crimp core geometry impact on strength under transverse compression and longitudinal shear are presented. Recommendations are given concerning selection of core structural parameters to increase its strength for the specified types of loading at the same volumetric density. Mechanical properties of panels with different composite cores are compared.     

Analysis of a coaxial gas ejector

In this paper, the results of investigating a coaxial gas ejector without increase of passive flow pressure are presented. A technique for calculation of coaxial ejectors has been developed. This investigation has resulted in the optimal structure of ejector with a high value of ejection coefficient.     

Calculation of process variables at composite Z-crimp shaping using the folding method

This paper presents a calculation technique for transformable tooling adjustment variables in the process of Z-crimp shaping from polymer composite prepregs. Equations for determining the position of structural tooling elements prior to crimping are obtained based on the conditions of equilibrium in the process of interaction between transformable mandrels and a raw packed sheet. The relations that allow calculation of tooling adjustment variables are presented.     

Simulation of <Emphasis Type="Italic">Z</Emphasis>-crimp shaping with the use of the ansys finite element software

A finite element model of the Z-crimp shaping from a hard sheet blank is developed and a number of calculations using the ANSYS finite element software is conducted. The calculations are carried out in the framework of elastoplastic behavior of the blank material using the classical model of bilinear kinematic (translational) hardening with corresponding parameters of elasticity and plasticity. The model takes into account kinematics of spatial transformation of the shaping equipment as well as the time-variable conditions of its contact interaction with the blank.     

皱褶结构芯格构型的几何设计方法

夹层结构具有较高的抗弯刚度质量比,较好的吸音、隔音、隔热和耐疲劳性能,被广泛应用于航空航天领域。夹层结构的芯材是具有一定抗剪刚度的轻质材料。从理论上讲,可以制造出各种不同构造型式的芯材。但由于工艺方法以及制造成本的限制,目前结构上常用的是由金属或非金属材料制成的六角蜂窝芯材。本文介绍了将平面板材通过按一定有规律的线系进行皱褶,从而形成各种不同构造型式、不同几何尺寸的等高度、变高度或曲面构型等复杂形状的芯材,用以满足各种不同的结构和功能性要求。而且,这种方法具有很好的工艺性。     

Cyclic folding of composite zigzag structures and calculating of equipment parameters

A novel processing scheme for cyclic production of composite folded structures from continuous sheet of prepreg is presented. A circular transformable mandrel is used as a shaping unit. A technique of calculating the shaping unit parameters is developed. It is based on the analysis of facility kinematics using a vector model of four-axis folded structures transformation process.