SiC粒子增强铸造Al基复合材料的研制

本文用真空烘烤封罐法对 SiC 粒子进行预处理,在固液两相区内搅拌添加,制造了铸造 Al 基复合材料。测试表明,该复合材料具有铸造性能好,力学性能高的优点,适用于采用压铸、石膏型精密铸造、金属型铸造等工艺方法成型的活塞、连杆等要求苛刻的零件。     

颗粒增强TiAl基复合材料及其Si的韧化作用研究EI

运用ＸＤ工艺制备了颗粒增强ＴｉＡｌ基复合材料。增强颗粒均匀分布于ＴｉＡｌ基体中并细化ＴｉＡｌ合金。通过在ＴｉＢ_２／ＴｉＡｌ、ＴｉＣ／ＴｉＡｌ复合材料中加入适量的Ｓｉ，颗粒增强ＴｉＡｌ基复合材料的室温延性得到了改善。     

体外CFRP筋预应力混凝土箱梁长期受力性能试验研究

碳纤维(CFRP)筋具有优异的物理力学性能,可用于替代传统的预应力钢筋。制作了体外配置碳纤维筋预应力混凝土箱梁模型,对持续均布荷载作用箱梁的截面应力重分布、长期挠曲变形及裂缝发展等规律进行了1001 d的试验观测。基于素混凝土柱体的实测徐变系数,运用双线性法和曲率法分别对试验箱梁的长期挠曲变形进行预测。试验结果表明:受压钢筋应变较初值增长225%～268%,受拉钢筋的应变较初值增长36.2～38.6%,混凝土表面压应变较初值增长164%～224%。按现行设计规范计算长期荷载作用特征裂缝宽度较实测值偏小11.8%～55.5%。跨中长期挠曲变形实测值为初始变形的2.32～2.42倍,较现行设计规范取值偏大18.5%。     

Handling of fine-particles by time-averaged particle driving method in plasmas

We developed a noble technique for the fine-particle handling in plasmas. In this method a pair of point electrodes are introduced in the plasma, to which positive pulses are applied alternatively. When the pulse repetition period is shorter than the particle response time, the particles feel only time-averaged force because of their large mass. Spatial profile of the equivalent potential of the time-averaged force varies from a circle to an ellipse with an increase in the local discharge at the electrodes. The particles are eventually transported toward a middle point between two point-electrodes, being almost independent of their initial positions. This method is quite effective for converging fine particles in the plasma.     

钢筋混凝土结构内的钢筋腐蚀监测

用钢筋混凝土修建的建筑物和构筑物，因受外界因素的影响，其内部钢筋可能会受到腐蚀而生锈，锈蚀严重者将危及安全。根据钢筋在混凝土内的锈蚀是一个电化学过程的特点，在不损伤钢筋混凝土结构的条件下，利用腐蚀监测仪，测量钢筋混凝的电化学特性值，并以此特性值绘制等值线图，利用该图能正确评估混凝土内钢筋受腐蚀的情况。     

Scale Transition in Steel-Concrete Interaction. II:?Applications

The proposed mode of consideration of the steel-concrete interaction (Part I) is applied to real-life engineering structures. Two structures recently investigated numerically at Vienna University of Technology are considered: (1) the reinforced concrete (RC) cooling tower III Ptolema?s SES (Greece) and (2) a part of the shotcrete tunnel lining installed at the Lainzer tunnel (Austria). In both examples, the uniaxial fracture criterion used in Part I is replaced by the maximum stress (Rankine) criterion. Together with the Drucker-Prager criterion, which is used for the simulation of compressive failure of concrete/shotcrete, it defines the space of admissible stress states in the framework of multisurface plasticity. For the simulation of early-age fracture of shotcrete, consideration of the steel-concrete interaction presented in Part I of this paper is extended towards young shotcrete. Similar to the benchmark problem investigated in Part I of this paper, several analyses with different degrees of consideration of the steel-concrete interaction are performed. The obtained results give insight into the influence of the steel-concrete interaction on the load-carrying behavior of the investigated structures.     

新岭大桥转体施工技术

新岭大桥采用有平衡重的平面转体法施工 ,这在我省尚属首例。施工中因地制宜采用拉链葫芦滑轮组进行牵引 ,仅用 3小时就使拱肋平稳、安全地转体就位 ,牵引施工获得成功 ,为我省的桥梁施工积累了经验 ,具有推广价值     

振动沉管挤密碎石桩在闸基处理中的应用

振动沉管挤密碎石桩是近十几年来在挤密砂桩和振冲桩的基础上发展起来的地基处理新技术,具有设备简单、操作方便、成本低、施工快、无污染等特点，被工程界广泛使用，积累了一定的工程经验。其在共产主义闸地基处理中的应用即为一例。     

钢筋混凝土防撞护栏早期裂缝成因分析及预防

从设计方面、施工方面及混凝土原材料的质量及配合比设计三方面分析了钢筋混凝土防撞护栏表面早期裂缝出现的成因,并提出了相应的预防措施,以有效防止护栏表面裂缝的产生。     

现浇混凝土构件与砌体接触面收缩和温度应力裂纹的探讨

分析讨论了建筑物由于收缩及温度应力而引起的过纹，提出了在设计施工中应考虑的问题和采取的防止措施。