舰艇新型宏观负泊松比效应蜂窝舷侧防护结构

提出一种具有宏观负泊松比效应的新型蜂窝舷侧防护结构,通过对负泊松比效应蜂窝胞元特殊结构构型设计,实现中等弹速下良好抗爆抗冲击性能。利用有限元动力学分析软件,研究鱼雷或导弹水下对舷侧防护结构的撞击侵入和穿透过程,对比研究了不同蜂窝构型、材料、胞元尺寸和胞壁厚度对舷侧结构抗冲击性能的影响。结果表明,蜂窝防护结构具有良好的抗冲击性能,负泊松比蜂窝构型较正泊松比蜂窝构型抗冲击性能更优。     

基于船体与设备一体化的设备抗冲击阈值

为了确定设备抗冲击阈值,基于主从系统耦合振动理论,以船用增压锅炉、齿轮箱为研究对象,将船体与设备的一体化抗冲击数值实验的数值统计特征进行分析。通过大量算例结果分析,提出将冲击作用下设备应力响应标准差作为设备失效判据,并给出了设备冲击作用下应力响应标准差最大值计算经验公式。     

Mechanical and Thermal Analysis of Composites Based on Rubbers From Used Tires

Summary : Reuse and recycling of tires at the end of their useful life is an environmental challenge owing to the huge volumes discarded all over the world. This paper tries to give a scientific contribution toward the mechanical recycling of elastomers derived from pre treatment of tires to produce anti-shock tiles and heat-insulating panels for civil applications. Thermal and mechanical results herein reported satisfactorily justify the interest devoted by now to this topic.     

A novel anti-shock silicon etching apparatus for solving diaphragm release problems

This paper presents a novel anti-shock bulk silicon etching apparatus for solving a universal problem which occurs when releasing the diaphragm (e.g.\ SiNx), that the diaphragm tends to be probably cracked by the impact of heating-induced bubbles, the swirling of heating-induced etchant, dithering of the hand and imbalanced etchant pressure during the wafer being taken out. Through finite element methods, the causes of the diaphragm cracking are analysed. The impact of heating-induced bubbles could be the main factor which results in the failure stress of the SiNx diaphragm and the rupture of it. In order to reduce the four potential effects on the cracking of the released diaphragm, an anti-shock bulk silicon etching apparatus is proposed for using during the last etching process of the diaphragm release. That is, the silicon wafer is first put into the regular constant temperature etching apparatus or ultrasonic plus, and when the residual bulk silicon to be etched reaches near the interface of the silicon and SiNx diaphragm, within a distance of 50--80~\mu m (the exact value is determined by the thickness, surface area and intensity of the released diaphragm), the wafer is taken out carefully and put into the said anti-shock silicon etching apparatus. The wafer's position is at the geometrical centre, also the centre of gravity of the etching vessel. An etchant outlet is built at the bottom. The wafer is etched continuously, and at the same time the etchant flows out of the vessel. Optionally, two symmetrically placed low-power heating resistors are put in the anti-shock silicon etching apparatus to quicken the etching process. The heating resistors' power should be low enough to avoid the swirling of the heating-induced etchant and the impact of the heating-induced bubbles on the released diaphragm. According to the experimental results, the released SiNx diaphragm thus treated is unbroken, which proves the practicality of the said anti-shock bulk silicon etching apparatus.