带扳手槽舱段轴向对接结构弯曲刚度的半解析分析

连接刚度是研究导弹结构动力学特性必须要考虑的重要因素。当前中小直径弹体结构较多采用带扳手槽的轴向螺柱对接连接形式,由于几何形状复杂和设计参数多,很难获得此类连接弯曲刚度的解析表达式。从弹性弯曲变形梁理论出发,提出了一种针对带扳手槽舱段轴向对接结构弯曲刚度的半解析分析方法。确定了中性轴的计算方法,推导了连接弯曲刚度的理论公式,并根据连接结构具有周向循环对称的特点,建立了1/n连接子结构的参数化模型,给出了轴向计算长度确定方法,利用非线性接触分析方法获得了子结构的拉、压刚度;将拉、压刚度代入理论公式,得到连接弯曲刚度。最后,通过正交试验研究了主要设计参数对弯曲刚度的影响。结果表明,半解析计算与整体结构有限元仿真计算所得弯曲刚度的相对误差最大为-13.86%,最小为-3.337%;在弯曲刚度的理论计算中,应根据实际拉、压刚度合理计算弯曲中性轴位置;在舱段直径(≤300 mm)一定时,连接厚度对弯曲刚度的影响最为显著,螺柱数目次之,相对而言,螺柱规格和预紧力水平的影响较小。

不同材料对圆柱滚花过盈联接连接强度的影响

针对有着光滑外表面的轴管和内孔加工出滚花的外包容件组成的联接进行研究,通过实验确定3种材料(40Mn2S、GGr15、E355)的性能参数,运用Abaqus软件分析3种不同材料对圆柱滚花过盈联接连接强度的影响。结果表明:圆柱滚花过盈联接连接强度与材料的关系为当材料的弹性模量较大时能获得较高的轴向及周向连接强度,但应力集中却趋于明显。

线型聚能切割器轴向直角连接射流形成特性

为了比较线型聚能切割器轴向内直角相连和外直角相连时的射流形成特性,采用数值模拟方法进行了射流形成研究,并通过实验进行了验证。结果表明:切割器外直角连接产生的片状射流在侧边和直角连接处之间逐渐由宽变窄,而且随着侧边射流的不断向前运动,连接处射流将被不断地向两侧拉伸,最终产生断裂,其侵彻能力相对侧边的射流减弱较大;而切割器内直角连接时,两侧片状射流均向内运动,在连接处碰撞形成速度较高的射流,其侵彻能力比两侧的射流要强,数值模拟结果与实验结果相吻合。由于容器在直角连接处部分的断面尺寸比其他部分容器壁的尺寸要大,在条件许可的情况下应采用轴向内直角相连从外部对容器或零部件进行切割。

Design and application of a new kind of rolling coupling

Based on Hertz theory of elastic contact and the design theory of ball bearings, a new type of rolling coupling was designed. The two halves of the rolling coupling can be moved relatively by a small axial force when a great moment is exerted on it. The rolling coupling was used to connect the principal axis and the decelerator of continuous extrusion machine and it can greatly decrease the harmful axial forces on the continuous machine. The engineering formulas for the contact stress and distance of apporach of the rolling elements were deduced and the method for designing the rolling couplings was proposed. The formulas for the forces exerted on the rolling element were verified by the experiment.

Experimental Research of Pressure Distribution in the Casing of Inducer

In this paper the inducer of the advanced-researched pump is studied. During multi-rotation speed experimentwith the medium of water, the dynamic pressures near inducer casing are obtained by transducer at each measuringpoint mounted on the casing along the axial direction, both in the steady rotation speed period and the up anddown period. Bases on analyses, the regularity of the axial distribution of time averaged pressure and pressurepulsation amplitude, the connection between pressure pulsation frequency and rotation speeds, and the relationshipbetween the pressure pulsation amplitude and the site of inducer blade are obtained.

化工静设备固定管板换热器是否设置膨胀节的探讨

固定管板换热器在化工静设备的应用中经常遇到需设置膨胀节的情况,本文简要介绍了如何通过调整管板、换热管、折流板间距等各计算参数确认是否需要设置膨胀节,并一一举例,分析各参数对计算结果的影响,实现固定管板换热器及膨胀节的合理设计。