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制孔工艺及其对航空合金微观结构和疲劳响应的影响
摘要 本文在航空合金孔加工的背景下对传统钻孔和螺旋铣削进行了比较研究，阐述了这两种不同的加工工艺对不同航空合金的微观结构和疲劳性能的影响。结果表明，与螺旋铣削工艺相比，两种合金在传统钻孔下都会经历更严重的表面/亚表面塑性变形。对于这两种合金，与传统钻孔相比，螺旋铣削可延长其试样疲劳寿命。在所有加工条件下，Al 2024-T3 的疲劳寿命明显长于 Ti-6Al-4V。使用冷却液通常可减少表面损伤，并可提高加工合金的疲劳性能。此外，还研究了加工表面粗糙度，以进一步阐述不同加工工艺的影响。
激光金属熔覆TC17合金激光冲击强化组织、残余应力及疲劳性能研究
摘要：激光冲击强化 (LSP) 已被用于通过激光金属沉积 (LMD) 来改善已修复的航空发动机部件的机械性能。本研究考察了横截面残余应力、微观结构和高周疲劳性能。结果表明，在激光熔化沉积区 200 µ m 深度处形成了 240 MPa 的压缩残余应力层，显微硬度提高了 13.1%。电子背散射衍射 (EBSD) 和透射电子显微镜 (TEM) 分析的结果表明，LSP 后取向差增加，位错特征明显，有利于提高疲劳性能。高周疲劳数据显示，与原 LMD 样品相比，LMD+LSP 样品的疲劳性能提高了 61%。因此，在航空航天领域，LSP 和 LMD 是修复高价值部件非常有效且很有前途的技术。
循环应力-应变行为分析、实验和...
疲劳、失效预测和疲劳性能的研讨会由 E-9 疲劳委员会下属的 E09.08 循环应变疲劳小组委员会主办，于 1971 年 12 月 7-8 日在佛罗里达州巴尔港举行。通用电气公司的 L. F. Coffin 和伦斯勒理工学院的 Erhard Krempl 担任联合主席。
通道轮廓激光策略对激光粉末床打印马氏体时效钢疲劳性能和残余应力的影响
观察到 160°C 的温度会略微降低疲劳寿命，这可能与马氏体时效钢的强度在 160°C 时略微降低有关 []。此外，正如预期的那样，带有机加工通道的样品在检查前没有破损样品，因此效果最佳。垂直样品首先断裂，而倾斜和水平样品的粗糙度较高。断裂分析表明，在部件核心和轮廓之间的垂直样品上有许多大于 100 微米的缺陷（图 12a 和 b）。这些缺陷在水平和 45° 样品上也可见，但数量较少。同样的缺陷也在显微照片上可见（图 12c）。因此，即使粗糙度和夹杂物也存在，起始点的根本原因是缺陷的存在
复合材料疲劳寿命预测方法
讲座-5 再生混凝土骨料及其对混凝土复合材料疲劳性能的影响 (SPS) 讲座-6 复合材料和结构疲劳寿命建模和预测的计算工具 (APV) 讲座-7 实际载荷条件下的疲劳寿命预测 (恒定寿命图) (APV) 第三天，星期三，2024 年 11 月 20 日 讲座-8 基于 GFRP 层压板的蠕变-疲劳相互作用损伤模型
POM纤维机场道面混凝土弯曲疲劳性能研究
摘要：聚甲醛（POM）纤维是一种新型聚合物纤维，可以改善机场道面混凝土的性能，其对混凝土弯曲疲劳性能的影响是其在机场道面混凝土应用中的一个重要问题。本研究采用普通性能混凝土（OPC）和纤维体积含量为0.6%和1.2%的聚甲醛纤维机场道面混凝土（PFAPC），在四个应力水平下进行了四点弯曲疲劳试验，以研究这些材料的弯曲疲劳特性。采用循环比（n/N）检查弯曲疲劳变形的变化后，进行了弯曲疲劳寿命的双参数威布尔分布检验。然后，考虑各种失效概率（生存率），构建了弯曲疲劳寿命方程。结果表明：POM纤维对机场道面混凝土的静载强度无明显影响，PFAPC与OPC静载强度差异在5%以内；POM纤维可使机场道面混凝土的弯曲疲劳变形能力提高近100%，但对机场道面混凝土的疲劳寿命有不同程度的不利影响，最大降幅达85%。OPC和PFAPC的疲劳寿命均服从双参数威布尔分布，考虑各种失效概率的单、双对数疲劳方程对双参数威布尔分布的拟合程度较高，R2均在0.90以上。PFAPC的极限疲劳强度比OPC低约4%。本次关于POM纤维机场道面混凝土弯曲疲劳性能的研究，对于将POM纤维推广到长寿命机场道面建设具有明显的研究价值。
制造工艺和...审批指南 - KR e-class
第 1 节。一般····················································································································· 3 第 2-1 节。轧制钢 ············································································································ 7 第 2-2 节。轧制钢半成品 ························································································ 15 第 2-3 节。用于高热输入焊接的轧制钢 ··········································· 17 第 2-4 节。YP47钢板········································································································· 19 第2-5节。具有改进的疲劳性能的船体结构钢 ····························· 21 第 3 节。钢管 ··································································································· 24 第 4 节。铸件和钢锻件·· ... ·· ...铜和铜合金管 ·············································································· 35 第 8 节。特殊铸铁阀门 ·· ... ·· ...船用链条附件····························································································· 44 第 10-3 节。海上链条和链条附件·································································· 46 第 11 节。钢丝绳· ... ·· ... ·························································································· 60
民用航空寿命预测的数字孪生 - SNC-Lavalin
与所述低保真方法提供的机会相比，高保真几何方法可能带来的部件疲劳寿命增加很小，而且投资成本要高得多。使用典型的航空航天制造公差范围进行的简单评估表明，部件寿命增量为±5％。这比低保真方法低两个数量级，但投资和所需数据量却大幅增加。这是因为固有材料疲劳性能取决于分子水平的部件几何形状。如果这是可能的，那么对任何飞机部件进行这种详细程度的扫描都会产生大量的数据；飞机结构由多少个部件组成，有多少个自由度？
制造工艺批准指南... - KR e-class
第 1 节。一般····················································································································· 3 第 2-1 节。轧制钢 ······································································································ 8 第 2-2 节。轧制钢半成品 ········································································ 16 第 2-3 节。用于高热输入焊接的轧制钢 ········································ 18 第 2-4 节。YP47钢板···································································································· 20 第2-5节。具有改进疲劳性能的船体结构钢····································· 22 第2-6节。焊接结构用高强度钢 ························································· 25 第 3 节。钢管 ·· ... ·· ... ·· ...铜和铜合金管··········································································· 44 第 8 节。特殊铸铁阀门·············································································································· 48 第 9 节。锚·· ...船用链条附件····························································································· 53 第 10-3 节。海上链条和链条附件····································································· 55 第 11 节。钢丝绳· ... ·· ...锅炉与压力容器··········································································································· 70