基本信息
项目批准号：51405309
申请代码：E0504
项目名称：基于搅拌摩擦修复的裂纹愈合机理及修复区疲劳断裂行为研究
项目负责人：王磊
依托单位：沈阳航空航天大学
研究期限：2015-01-01 至 2017-12-31
资助经费：25.0（万元）

项目摘要
中文摘要：
由裂纹引起的机械零部件及金属结构的断裂，是工程中最危险、最常见的失效模式。与现有方法相比，搅拌摩擦裂纹修复具有独特的优势，但裂纹愈合机理尚不明确。课题针对2A12铝合金表面裂纹及贯穿裂纹实施搅拌摩擦修复，采用实验和数值模拟相结合研究不同修复工艺参数下温度场、热塑性材料流场和搅拌头与修复件间作用力的变化规律；立足于对裂纹愈合物理机制及机理的科学表述，借助显微分析、物理模拟与分子动力学仿真深入研究修复区微观组织、二次相、位错等在修复过程中的变化，追踪裂纹形态演变。基于疲劳断裂理论，定量分析裂纹修复效率，运用统计分析建立修复参数与修复件疲劳寿命的数学模型；考虑修复过程热影响，对裂纹扩展Paris模型进行修正，在修复裂纹的同时以期实现材料与结构性能的强化。
英文摘要：
Fracture of mechanical components and metal structures caused by cracks is the most dangerous and common failure mode. Friction stir crack repairing has unique advantages compared with existing methods, but the crack healing mechanism is still indefinited. Surface cracks and through cracks of 2A12 aluminium alloy will be friction stir repaired during which the variation of temperature distributions, thermoplastic material flow patterns and force fileds will be studied through experimnets and numerical simulations. Microscopic analysis, physical and molecular dynamics simulations will be introduced to study the evolution of microstructures, secondary phases, dislocations and crack shapes etc. Crack repairing efficiency will be quantitatively assessed based on the fatigue fracture theory, mathematical model of relationship between repairing parameters and fatigue lives of the repaired specimens will be built through statistical analysis. A corrected Paris model considering heat effect will be proposed as well. By repairing the crakcs using friction stir method, the strengthen of materials and structures will be expected at the same time.
                                                                                                                                                                       ——来自https://kd.nsfc.gov.cn/