Effect of post-peak cyclic load on mechanics and seepage characteristics of sandstone under different confining pressures [PDF]
, 2023 The mining disturbance causes the rock mass in a certain range of the coal seam floor to be in a post-peak state. Due to the excavation of adjacent roadways and the mining of coal seams, the post-peak rock mass undergoes a cyclic loading-unloading ...
Daqiang XU +7 more
core +1 more source
Design and experimental research of pipeline stress measurement system based on alternating current field [PDF]
, 2023 Ferromagnetic pipelines are prone to stress distortion during service, which will likely cause destructive defects, such as fatigue damage and cracks, and even major safety accidents in severe cases.
Anquan WANG +7 more
core +1 more source
Jianzhu Gangjiegou Jinzhan, 2023 国内在高强冷弯厚壁型钢的冷作硬化效应和残余应力分布领域的研究还十分有限，基础数据匮乏。针对这一问题，对高强冷弯厚壁C形钢展开研究，对其母板及冷弯型钢构件的材性进行拉伸试验研究，得到母板和型钢截面不同部位的屈服强度及断后伸长率等指标。研究结果表明：冷作硬化效应在弯角部位更明显；冷作硬化效应的强弱主要与母板屈服强度、母板强屈比、型钢弯角内半径及壁厚等因素有关。采用“切割法”对冷弯型钢的纵向残余应力进行研究，根据实测数据绘制残余应力沿型钢全截面的分布曲线，并研究影响残余应力分布的主要因素 ...
李功文, 邵剑锋
doaj
深冷处理对7050铝合金尺寸稳定性及断裂韧性的影响 [PDF]
, 2019 研究了不同深冷处理工艺对7050铝合金尺寸稳定性和断裂韧性的影响。采用圆环开口方法对尺寸稳定性进行评价,对比了不同深冷处理工艺对尺寸稳定性的改善效果,从材料析出的角度分析了提高尺寸稳定性的深冷处理机理,并对微观组织的变化进行了分析。通过研究探索出了7050铝合金的最佳深冷处理工艺为-150℃×24 h,2次,尺寸稳定性提高了77. 9%,同时断裂韧性提高13.
刘轩之 +5 more
core +1 more source
Effect of local induction heating on secondary roll-forming of high strength square tubes [PDF]
, 2016 The formability of corners was improved by heating the corner area of high strength square tubes with induction coils.Under the premise of not impacting the undeformed zone,we obtained the ideal sectional dimension,microstructure and properties of ...
CHEN Qiang +5 more
core +1 more source
Energy-accumulation blasting and water injecting under local water storage and pressure retention in heading face [PDF]
, 2023 Due to the poor effect of local energy-accumulation blasting and water injection in the Xuehu Coal Mine and the undetermined influence range of local energy-accumulation blasting and water injection pressure relief, the spacing of blasting holes cannot ...
Tao ZHANG, Yu WANG, Zhenfeng WANG
core +1 more source
Research on Key Issues in Eddy Current Nondestructive Evaluation of Residual Stress in Aluminum Alloy [PDF]
, 2015 铝合金作为制造业发展的基础材料，在航空航天、高速铁路、建筑工程、船舶制造、汽车工业等支柱产业中有着重要地位。残余应力往往是造成铝合金结构破坏的重要因素。有效的评价应力状态，特别是导致损伤出现的临界应力状态是评价设备结构强度、可靠性的重要依据。传统的无损检测方法已广泛应用于工程实际中，但大部分局限于对已成型的缺陷进行检测。对于可能导致损伤出现的隐性、不规律变化的残余应力状态的评价则较为困难。 目前，应用较多的残余应力检测法主要有盲孔法、X射线法、超声波法以及磁测法。这些方法在使用上都存在很大的局限性 ...
汪涛
core
Assessment of wind-induced fatigue crack initiation life at guyed mast earplate joints considering welding residual stresses [PDF]
, 2010 A new method for assessing the degree of the cumulative fatigue crack initiation damage of the welds of earplate joints of a guyed mast,which connect the mast with the cable,is proposed.Based on the multi-scale wind-induced stress analysis of the ...
Pi, Y, Qu, W, Wang, W
core
Jianzhu Gangjiegou Jinzhan, 2023 对接焊缝为钢结构典型的焊缝形式，其位置处的裂纹和气孔型缺陷准确检测对于维护钢结构有着重要的意义，使用磁记忆检测技术对焊缝裂纹和气孔型缺陷进行定位时，传统的零点极值理论会由于焊接残余应力的影响，难以区分残余应力和焊接裂纹和气孔型缺陷所产生的磁信号，使其在实际检测中造成缺陷定位的误判和漏判，因此，从焊接裂纹和气孔型缺陷和残余应力所在区域磁信号产生机理的不同入手，开展考虑残余应力影响下的焊接裂纹和气孔型缺陷定位检测研究。首先对焊接残余应力与裂纹和气孔型缺陷产生磁信号的机理进行分析 ...
陈悦, 潘学豪, 邓淋方
doaj
Research on residual stress measurement and vibration stress relief of sheet metal [PDF]
, 2017 小孔法的塑性效应会给高残余应力测量带来误差，为了解决这个问题，论文中对ASTME837-13a标准中的校准系数的塑性修正进行了研究。同时，组建了用于金属薄板件振动时效的电磁激振系统，研究了振动时效消除金属薄板件的残余应力。论文的研究内容围绕以下几个方面展开。 首先，研究了小孔法测量铝合金构件高残余应力的塑性效应修正方法。基于形状改变比能密度理论，对ASTME837-13a标准中的校准系数进行塑性修正；结合双线性弹塑性理论，采用ANSYS软件进行有限元仿真标定；使用电子万能试验机进行拉伸加载实验验证 ...
林俊辉
core