He YANG
,
Yuli LIU
,
Wang CAI
,
Mei ZHAN
材料科学技术（英文）
Blade precision forging is a high temperature and large plastic deformation process. Interact of deformation and heat conduction results in producing large temperature unevenness inside the billet. The unevenness has a great effect on the mechanical property and microstructure of the forged blade. However, internal quality of the blade is decided by its microstructure, it is necessary to conduct a research on the microstructure of the blade forging process. Taking a blade with a tenon as an object, its precision forging process is simulated and analyzed using a 3D coupled thermo-mechanical FEM code. And based on the prediction model of Ti-6Al-4V presented by the predecessor, a study of the evolution of grain size in the forging process is made. The distribution characteristics of grain size in typical sections are obtained under various deformation degrees. This study may provide a base for designing the blade forging process and working out its parameters.
关键词:
Blade
,
null
,
null
,
null
Shude Ji Liguo Zhang Xuesong Liu Jianguo Yang
材料科学技术（英文）
On basis of the subsection welding and the local heating´s reasonable technological parameters obtained by plane experiment, the welding residual stress field of some Francis turbine runner is regulated and controlled. For the experimental plane with a thickness of 16 mm, the effect of subsection welding on decreasing welding residual stress of the prior welding section is obvious when the distance is less than 50 mm away from the end of latter welding section. For the local heating, the best position, where the effect on decreasing the welding residual stress of plane is best, is 60 mm or so away from the edge of heating area. The experimental results of runner show that the subsection welding can make the residual compressive stress engender in the blade dangerous area while the stress value is greatly influenced by the length of the welding section of blade outlet. The local heating can further decrease the value of residual stress near blade outlet, while the local heating processed after heat treatment is better than that processed before heat treatment.
关键词:
Blade
贺继林
,
李栋
,
郑海华
宇航材料工艺
doi:10.3969/j.issn.1007-2330.2014.02.004
根据热传导、复合材料力学和固化动力学理论,采用基于偏微分方程的强耦合多物理场有限元方法,计算在F650双马来酰亚胺树脂建议温度周期下直升机复合材料桨叶固化过程中温度、固化度、固化度反应速率和内应力变化历程.通过仿真结果对温度周期进行优化调整,改善工艺过程.计算结果表明:桨叶中树脂固化反应同步度高,交联反应产热量少;调整后的加热周期与建议加热周期相比,最高加热温度由460 K降低为393 K,但固化度由0.1增加到l的反应时间只由25 min增加为30 min,固化反应速率峰值从1.35×10-3/s降低为1.15×10-3/s,PMI(聚甲基丙烯酰亚胺,Polymethacrylimide)泡沫的Von Mises热应力最大值从0.82 MPa降低为0.482MPa.
关键词:
复合材料
,
固化
,
有限元分析
,
桨叶
,
双马来酰亚胺树脂
,
多物理场耦合
韩露
,
于翔天
,
王影
,
谢国君
,
逄锦程
宇航材料工艺
doi:10.12044/j.issn.1007-2330.2017.01.014
叶片在安装试运行过程中发生断裂,断裂位置位于叶根附近,通过对故障件的观察、测试与分析,确定了叶片发生低周疲劳断裂的原因是由于生产过程中工艺控制不良,叶片根部局部区域树脂固化不完全,导致该区域的强度、刚度极低,当受到疲劳载荷作用时在结构应力集中区域首先发生分层开裂、扩展直至最终失稳断裂.同时指出固化不完全的原因.
关键词:
叶片
,
疲劳断裂
,
树脂
,
纤维
,
固化
