A thermal-elastic analysis on laser-induced reverse bulging and plugging in circular brass foil

A new failure mode is observed in circular brass foils induced by laser beam. The new failure is based on the following experimental facts : (1) the peripheries of the circular brass foils are fixed and the surfaces of the foils are radiated by laser beam ; (2) the laser beam used is considered to be non-Gaussian spatially, actually an approximately uniform distribution limited in a certain size spot ; (3) the pulse on time of laser beam should be 250 μs, i.e. so called long duration pulse laser. The failure process consists of three stages ; i.e. thermal bulging, localized shear deformation and perforation by plugging. The word reverse in reverse bulging and plugging mode means that bulging and plugging occur in the direction of incident laser beam. To study the newly-discovered type of failure quantitatively, analytical solutions for the axisymmetric temperature field and deflection curve are derived. The calculated results show that the newly discovered failure mode is attributed to the spatial structure effect of laser beam indeed.

Shear deformation analysis on laser-induced reverse bulging and plugging

A new kind of failure mode is observed in circular brass foils in which their peripheries are fixed and their surfaces are subjected to a long pulsed laser over a central region. The failure is classified into three stages; they are referred to as thermal bulging, localized shear deformation and perforation by plugging. A distinct feature of the failure mode is that bulging and plugging occurred in the direction opposite to the incident laser beam. To study the failure mode, we investigate the non-linear response of heated, non-homogeneous circular plates. Based on the large deflection equations of Berger [J. Appl. Mech. 22 (3), 465-472 (1965)], Ohnabe and Mizuguchi [Int. J. Non-Linear Mech. 28 (4), 365-372 (1993)] and the parabolic shear deformation theory of Bhimaraddi and Stevens [J. Appl. Mech. 51 (1), 195-198 (1984)], we have derived new coupled governing equations of shear deformation and deflection. The new equations are solved, for the plate with a clamped edge, by the Galerkin and iterative methods. The numerical results for the shear deformation distribution are in good agreement with the experimental observation.

渤海4号钻井船的疲劳损伤计算与分析

文章对渤海４号钻井船在我国渤中、辽东湾、东海和南海４大海域作业的疲劳损伤进行了详细的计算和分析，讨论了平台薄弱部位桩靴加强程度对平台疲劳损伤大小的影响及海流对平台损伤的作用。最后对渤海４号进行了充分的技术经济评价，为今后平台的合理使用、经济使用、安全作业提出了重要的建议。

涠11-4平台结构动态响应监测结果分析(涠11-4平台原位监测研究之二)

本文总结了针对涠１１－４平台一年多时间的应变和加速度监测数据的处理分析工作，详细介绍了所用的数据处理方法，给出了应变数据的统计结果及长期分布规律。通过对应变和加速度信号进行频谱分析，揭示了平台在多种环境条件下的振动特性。

涠11-4平台综合强度监测技术及实施运行系统(涠11-4平台结构原位监测研究之一)

本文介绍了一种固定式导管架平台综合强度监测系统，它用于对涠１１－４平台关键部位的应力、加速度及与结构响应相关的环境参数进行长期监测。讨论的重点内容是结构响应的测量方案、设备及实施方法，并对运行结果作了说明

以1-苯基-3-甲基-4-苯甲酰基代吡唑酮[5]萃取稀土和钍铀钛锆及其在分析化学中的某些应用

本文研究了以PMBP-苯萃取稀土和钍、铀、钛、锆的萃取行为。测定了La、Ce、Pr、Nd、Sm、Gd、Dy、Yb、Y、U(Ⅵ)、Ti、Th和Zr的pH_(1/2)值,计算了它们的萃取平衡常数。并介绍了近十年来作者将此萃取剂应用于铀、钍、稀土、鋰、钢铁合金及岩石中痕量稀土、钍和钙的分离和测定方面的工作。实践证明,PMOP合成简便、价格低廉、萃取能力较强,是比TTA更为优越的萃取剂。

Circular brass foil failed by plugging opposite to direction of incident laser beam

The peripheries of circular foils of 30 mm in diameter and 0.1 mm thick are fixed while their surfaces are subjected to a long pulsed laser over a central region that may vary from 2 mm to 6 mm in diameter. Failure is observed and classified into three stages; they are referred to as thermal bulging, localized shear deformation, and perforation by plugging. A distinct feature of the failure mode is that bulging and plugging occurred in the direction opposite to the incident laser beam. Such a phenomenon can be expected to occur for a laser intensity threshold value of about 0.61 x 10(6) W/cm(2) beyond which local melting of the material begins to take place.

KD-4型可动凝胶调驱体系研究与应用

针对中高温油藏调驱中使用的含醇类酚醛树脂类交联剂在现场应用中存在结块、醇的挥发性等问题，开展了可动凝胶合成技术、配方组成、成胶时间、热稳定性考察等试验研究，形成了以全水溶、高羟甲基化的预聚树脂交联剂为主体的KD-4型调驱体系配方。对KD-4型调驱体系成胶时间、热稳定性等进行了室内实验，并开展了前置段塞物模试验和可动性物模试验研究。依据试验结果，将总体段塞设计为“前置段塞＋主段塞＋保护段塞＋驱油段塞（视井况而定）”，成胶黏度由低到高。自2006年7月以来，该技术进行了6口井的现场应用，井组有效率100％，截至2007年10月底，按驻点法统计，累计阶段增产原油16158．7t，目前继续有效，措施效果显著，说明调驱性能稳定，方案设计科学.

PZT-4紧凑拉伸试样的断裂分析

基于线性压电材料的复势理论,通过解析分析,导出了一种分析有限压电板裂纹问题的解析数值方法.首先,计算了含中心裂纹有限板的断裂参数,与Woo和Wang的解析数值法(Int J Fract,1993,62:203～218)相比较,表明该方法具有很高的精度和很好的计算效率.随后,采用该方法和有限元法计算了PZT-4紧凑拉伸试样在绝缘裂纹面边界条件下断裂时的断裂参数,发现各断裂参数的临界值分散性很大,不能作为压电材料的单参数断裂准则.进而,针对试样真实的裂隙形状,采用有限元法计算了裂隙尖端的应力、电位移场,比较了裂隙内介质的介电性能对裂隙尖端场的影响,计算了带微裂纹的真实裂隙模型的断裂参数并进行了理论分析.

“神舟4号”飞船搭载微重力流体物理实验获得圆满成功

由中国科学院力学研究所胡文瑞院士和解京昌研究员领导的研究小组承担的“微重力液滴热毛细迁移实验”项目，利用自行研制的“通用流体实验装置”，于2002年12月30日搭载“神舟4号”飞船，圆满完成了各项预定空间实验任务。对飞船下传数据和图像的初步分析表明，实验装置全部工作正常，实验获得了圆满成功，可望得到有价值的学术成果，并在相关理论研究中取得突破。此次空间实验的成功，显示了科学家和工程师的完美结合，标志着力学所在“两弹一箭”后重返空间技术领域，再铸辉煌！

滦县M_L=4.8地震的局部多台数字记录

据中国数字地震台网测定,2004年1月20日16时34分11.9秒在滦县发生了ML=4.8的地震,震中位于东经118.77°,北纬39.71°,震源深度H=10km。尽管地震造成的破坏轻微,但有感范围较大,在秦皇岛市、青龙县、北京市、廊坊市、天津市等地均有震感。这次地震使震中及其附近地区的5台数字强震仪触发,记录了5组3分量数字加速度记录。本文对这次地震事件、地震地质概况作了简要介绍,并就台站(阵)基本背景资料、数字强震仪主要技术指标作了详细说明。最后,对获取的15条数字加速度记录作了初步处理分析,如基线校正、加速度峰值计算、傅里叶谱及反应谱计算等。