Lug joints are preferred joineries for transferring heavy loads to parent components in aerospace vehicles.They experience corrosion due to environmental conditions,improper surface finishes and rubbing displacement b...Lug joints are preferred joineries for transferring heavy loads to parent components in aerospace vehicles.They experience corrosion due to environmental conditions,improper surface finishes and rubbing displacement between the pin and lug-hole.This causes damage of different sizes and shapes near the lug-hole.Stiffness degradation due to corrosion-induced damage is modelled as a through-pit at one of the identified critical locations through stress analysis.The effect of this pit on fatigue crack initiation life is estimated.Lug-hole is pre-stressed by cold-working and the benefits of inducing plastic wake on the intended performance of the lug joint during the damages due to corrosion are brought out and compared with non-cold-worked lug-hole.Numerical analysis is performed on this lug joint with pressfit.The results obtained highlight the benefits of cold-working and the methodology can be extended to damage growth and analyse the effect of surface treatments for better structural integrity of components of aerospace vehicles.展开更多
The elastic limit of single-phase alloy Nb-2Mo-2Zr-1Ti is higher as recovered state in comparison with as cold-rolled or recrystallized one.For Nb-40Ti-5.5AI alloy of age-hardening type,the elastic limit is lower as c...The elastic limit of single-phase alloy Nb-2Mo-2Zr-1Ti is higher as recovered state in comparison with as cold-rolled or recrystallized one.For Nb-40Ti-5.5AI alloy of age-hardening type,the elastic limit is lower as cold-rolled state,but increases considerably after proper aging.However,its elastic modulus changes no more,so the stored-energy (σ_e^2/E)may raise significantly.The temperature dependence on elastic modulus for pure Nb as intensely cold-worked or recrystallized state is anomalous.This anomaly may disap- pear after recovered treatment of intensely cold-worked state at 600℃ for 4 h.and may change no more after that of recrystallized state.The anomalous behaviour of elasticity was also discussed on the non-magnetic Nb.展开更多
本工作采用超高真空气相氢渗透技术,在140—400℃温度范围内,测定了氢在纯 Ni(不同冷变形量)中的渗透率、扩散系数和溶解度常数,研究了冷加工对氢渗透和扩散行为的影响。结果指出,在实验温度范围内,氢在纯 Ni 中的渗透率和扩散系数均遵...本工作采用超高真空气相氢渗透技术,在140—400℃温度范围内,测定了氢在纯 Ni(不同冷变形量)中的渗透率、扩散系数和溶解度常数,研究了冷加工对氢渗透和扩散行为的影响。结果指出,在实验温度范围内,氢在纯 Ni 中的渗透率和扩散系数均遵循 Arrhenius 方程,纯 Ni 的冷加工对氢渗透和扩散行为没有明显影响。展开更多
文摘Lug joints are preferred joineries for transferring heavy loads to parent components in aerospace vehicles.They experience corrosion due to environmental conditions,improper surface finishes and rubbing displacement between the pin and lug-hole.This causes damage of different sizes and shapes near the lug-hole.Stiffness degradation due to corrosion-induced damage is modelled as a through-pit at one of the identified critical locations through stress analysis.The effect of this pit on fatigue crack initiation life is estimated.Lug-hole is pre-stressed by cold-working and the benefits of inducing plastic wake on the intended performance of the lug joint during the damages due to corrosion are brought out and compared with non-cold-worked lug-hole.Numerical analysis is performed on this lug joint with pressfit.The results obtained highlight the benefits of cold-working and the methodology can be extended to damage growth and analyse the effect of surface treatments for better structural integrity of components of aerospace vehicles.
文摘The elastic limit of single-phase alloy Nb-2Mo-2Zr-1Ti is higher as recovered state in comparison with as cold-rolled or recrystallized one.For Nb-40Ti-5.5AI alloy of age-hardening type,the elastic limit is lower as cold-rolled state,but increases considerably after proper aging.However,its elastic modulus changes no more,so the stored-energy (σ_e^2/E)may raise significantly.The temperature dependence on elastic modulus for pure Nb as intensely cold-worked or recrystallized state is anomalous.This anomaly may disap- pear after recovered treatment of intensely cold-worked state at 600℃ for 4 h.and may change no more after that of recrystallized state.The anomalous behaviour of elasticity was also discussed on the non-magnetic Nb.
文摘本工作采用超高真空气相氢渗透技术,在140—400℃温度范围内,测定了氢在纯 Ni(不同冷变形量)中的渗透率、扩散系数和溶解度常数,研究了冷加工对氢渗透和扩散行为的影响。结果指出,在实验温度范围内,氢在纯 Ni 中的渗透率和扩散系数均遵循 Arrhenius 方程,纯 Ni 的冷加工对氢渗透和扩散行为没有明显影响。
