Numerical modelling for scattering of waves in three-dimensional cracked material

In this paper, a mathematical model is proposed for the problem of the scattering of plane waves in a three-dimensional cracked materials. Instead of obtaining closed-form solutions as in conventional theoretical analysis methods, this approach, called the Equivalent Nodal Force (ENF) method formulates the mechanical effects of cracks as an equivalent nodal force in a numerical procedure, and physically translates cracked material into an equivalent continuous one. Several mechanical relations between waves and cracks are evident from this method. Also the results of several numerical calculations are presented and these are compared with those obtained by the conventional methods.     

重力坝深(底)孔断面钢筋混凝土模型试验研究

文通过7个小尺寸和1个大尺寸的钢筋混凝土断面模型试验，研究重力坝深(底)孔在坝体自重和内水压力以及超内水压力作用下的结构特性和破坏规律。重点探讨混凝土和钢筋应力应变、混凝土开裂、裂缝宽度和裂缝扩展规律，为建立更为科学的孔口配筋理论提供依据。     

Fundamental solutions for half plane with an oblique edge crack

An elastic half plane with an oblique edge crack is considered in this paper. A pair of concentrated forces or point dislocations is assumed to act at an arbitrary point in the half plane. The half plane with an edge crack is first mapped into a unit circle by a rational mapping function so that the following analysis can be carried out on the mapped plane analytically. Then the complex stress functions are derived by separating the whole problem into two parts; one is the principal part corresponding to the infinite plane acted on by concentrated forces or dislocations, the other is the holomorphic part, which can be determined by making use of the property of regularity of complex stress functions. The stress intensity factors of the crack can be calculated with different inclined angles of the crack, and the displacement and stress components at an arbitrary position in the half plane can be expressed explicitly.     

铅黄铜水平连铸棒材熔铸工艺的试验研究

在工业生产条件下，对影响HPb59－1水平连铸律材热轧开裂的熔铸工艺进行了试验研究．取三个熔铸工艺因素：铸造速度、冷却水压力、冷却水温度．试验结果表明；铸造速度对热轧开裂影响极为显著，使其控制在410mm／min左右可获得较为理想的效果．     

钢筋钢纤维增强部分混凝土梁受剪性能试验研究

本文通过钢筋混凝土梁以及在受拉区部分地加入钢纤维的钢筋混凝土梁的试验及理论分析，研究了钢纤维混凝土层厚、钢纤维体积率和剪跨比对钢筋钢纤维增强部分混凝土梁受剪性能的影响，建立了与普遍钢筋混凝土梁受剪承载力计算公式相衔接的钢筋钢纤维增强部分混凝土梁受剪承载力的计算模型和计算公式．     

ANALYSIS ON ROOM TEMPERATURE TENSILE STRENGTH OF δ-Al_2O_3, FIBER / Al-12Si COMPOSITE

对δ－Ａｌ２Ｏ３纤维／Ａｌ－１２Ｓｉ复合材料室温拉伸强度的分析表明，在实验条件下该复合材料存在δ－Ａｌ２Ｏ３纤维的最小体积分数Ｖｍｉｎ和临界体积分数Ｖｃｒｉｔ，并求出其基体强度δｍ和室温强度σｃ－δ－Ａｌ２Ｏ３纤维体积分数Ｖｆ直线方程及纤维的临界长度ｌｃ和复合材料的剪切应力τＰ确定复合材料的ＲＯＭ预测曲线，应首先判断σｍ是否等于未增强合金的强度σｕｍ才能得出正确的结论。     

An investigation of pore cracking in titanium welds

Two welded Ti-6A1-4V pressure vessels leaked prematurely in service. The leaks were caused by cracks emanating from weld porosity. The cracks originated during fabrication, with subsequent growth in service leading to the formation of the leak paths. Pore cracking is thought to be caused by a mechanism that involves both sustained-load and cyclic contributions, with the former being the more prominent. It is shown that the tendency for cracking is influenced by pore position and that pore size is not a deciding factor in that regard. The factors that govern pore cracking are discussed, and the possible role of interstitial embrittlement is assessed.     

新一代高强韧性WDL系列钢综合性能及应用

本文着重介绍武汉钢铁公司近年来研制开发的第二代高强度低合金钢—高强韧性WDL系列钢的综合性能及应用情况。该钢具有优异的焊接性能和低温韧性,板厚≤50mm钢板焊前不预热或稍加预热而不产生焊接裂纹,是制造大型压力容器（特别是低温和常温球罐）、水电站压力钢管和水轮机蜗壳、高寒地区使用的大型工程机械、大跨度桥梁及海上采油平台等装备的理想用材。