Evaluation of tensile properties of a compositemetal joint with a novel metal insert design by experimental and numerical methods

Composite-metal joints with a metal insert are one kind of connecting structure.In this paper,tensile experimental tests were carried out to investigate tensile properties of a composite metal joint with a novel metal insert design.Finite element models of the joint were established,and strain distribution and tensile strength were analyzed.The numerical results are in good agree ment with the experimental results.Results show that the joint failure is dominated by shear properties of the resin layer.Increasing the resin layer thickness in a certain range will improve the tensile strength of the joint,while increasing the radius of the fillet on the ending side of the metal insert will decrease the joint strength.Increasing the resin layer plasticity will improve the joint strength.The effect of the embedded depth of the metal insert can be ignored.     

The Ultra Heavy Elements in the Cosmic Radiation

The concept that nuclei of all of the elements in the periodic table were accelerated to relativistic energies in the primary cosmic rays was confirmed by the discovery of the presence of nuclei significantly heavier than iron. These “ultra heavy” nuclei must all have been synthesized in endothermic reactions, occurring predominately in the final stages of stellar evolution. Determination of the relative abundances of these nuclei should provide new insights into the nuclear processes in some of the most energetic events in the life cycle of stars. The very low abundances of these nuclei relative to those of the exothermic lighter nuclei have made progress difficult. In addition, the effects of apparent preferential acceleration mechanisms and of propagation through the interstellar medium have distorted the source abundances. The history of the original discovery of the presence of these nuclei will be followed by a summary of the present state of knowledge of the observed abundances. The effects of acceleration biases and of interstellar propagation will be discussed. Finally some of the possibilities for further advances will be outlined. A copy of the Power Point presentation for this talk is available on request.     

当代金属类阻尼材料及其应用

论述了金属类阻尼材料的减振降噪机理，介绍了具有代表性的各种阻尼材料的物理机械性能，以及它们的应用情况等。     

颗粒增强金属基复合材料凝固过程中的颗粒推移效应

归纳了颗粒增强金属基复合材料凝固过程中颗粒推移效应的各判据,分析了各自的适用范围,提出了实际复合材料铸件中抑制颗粒推移的途径。     

碳化硅／铝复合材料板的耐环境腐蚀性能研究

对固态热压和挤压铸造的 SiC_f/Al、SiC_w/Al 和 SiC_p。/Al 复合材料板,在3.5%NaCl 溶液及饱和盐雾气氛中的耐腐蚀性能进行了研究;并分析了影响耐腐蚀性的主要因素.研究结果表明,SiC_f/Al 板具有良好的耐腐蚀性,试样表面光洁度、内部一次和二次界面的结合情况是影响这类板材耐腐蚀性的主要因素。SiC_w/Al-ZL105和SiC_p/Al-ZL105板在75℃、3.5%NaCl 溶液中具有优良的耐腐蚀性能,预制件中的“气泡”将对这种复合材料的耐蚀性带来不利影响,在用预制丝挤压铸造的 SiC_f(Al-L2)/Al-ZL105板中,提出了“界面阶梯腐蚀”规律.在75℃盐水中浸泡15d 后的 SiC/Al复合材料板的尖角、刃边、二次加工孔周围仍无明显变化,且无分层现象.     

金属氢化物冷源传热传质分析

为了验证冷源系统是否能满足出舱航天服的需要，本文针对一套开放式金属氢化物冷源系统，建立数学模型，对其制冷和再生阶段的传热传质过程进行了分析。研究结果表明，金属氢化物热泵能够满足宇航员出舱活动中的散热要求，其体积与水升化器相当，质量损失小，并且能够通过控制反应床的压力调节出口水温，可控性良好，而在返回舱内后，调节冷却水流量，反应压比，可以使氢化物在30min内再生。     

航天器用新型金属橡胶减振器

介绍了一种用于航天器的新型金属橡胶减振器（MRD）的制作工艺，并与普通橡胶减振器（RD）在航天环境中的使用寿命、阻尼、能量耗散和传递率等性能进行了比较。分析结果表明，MRD的性能具有明显的优势，在航天等特定领域内MRD是RD的理想替代品。     

样条函数康托诺维奇法在复合材料板和圆柱曲板弯曲中的应用

样条函数康托诺维奇法是最新提出的一种数值型(或离散型)的康托诺维奇法。它既能化二维问题为一维问题,同时又具有样条函数法收敛快精度高,处理边界条件方便及平板曲板问题通用等优点。本文在板、壳勒夫——柯希霍夫假设的基础上,推导出金属、复合材料板、壳弯曲问题的基本公式。大量数值计算从各方面证明了本方法具有良好的使用性能。     

颗粒增强型金属基复合材料的研究进展

金属基复合材料目前正在朝着大规模商业化的方向发展，颗粒增强型金属基复合材料以其低成本、优良综合性能的特点处于发展的前列。列举了典型材料的性能特点；分析了颗粒增强型金属基复合材料在航天结构中的应用及其在应用过程中存在的一些问题及改进措施；最后展望了金属基复合材料工程应用的前景。     

三波长辐射温度计

采用辐射法测量物体表面真实温度的最大困难是被测材料表面的发射率难测。三波长辐射温度计能消除发射率对测温的影响,尤其是对抛光表面的测温。本文基于推导多波长辐射温度计的理论,推出了一种三波长辐射测温法的新关系式,并建立了三波长辐射温度计的数学模型。