【作者】 韩芸；

【导师】 佟福山；

【作者基本信息】 哈尔滨工程大学 ， 船舶与海洋结构物设计制造， 2003， 硕士

【摘要】 本文说明了强度稳定综合理论中的切线模量因子、比例极限定律和强度利用率函数等概念是弹性力学有关概念的延伸，既可以用于强度理论，也可以用于稳定理论。 利用应变能定理的概念对切线模量理论进行了新的论证和应用，进一步完善了强度稳定综合理论。 探讨了强度稳定综合理论用于疲劳寿命计算的方法。通过材料力学疲劳性能曲线和断裂力学之间有关参量间的演变关系，得到了疲劳寿命与裂纹半长的关系，即疲劳寿命的折算裂纹长度，建立了两者之间的函数关系并利用这个函数关系说明了疲劳寿命的切线模量因子法，能反映各种材料疲劳寿命的共同变化规律，试验数据可在不同材料之间互相参考使用，具有重大意义。 对已有的材料力学疲劳性能试验曲线进行分析整理，利用试验数据绘制了相对应力应变曲线、切线模量因子曲线和疲劳寿命曲线，利用这三种无量纲参数曲线发现了其中存在的规律性，即在某种程度上实验曲线可以互相取代，并用试验数据对此进行了讨论，并由此推断，如果找出材料彼此的共性或彼此之间的系统误差就可以将一种材料的试验曲线供其它材料参考使用，这是一种估算材料的疲劳寿命的简便方法，对工程而言具有实用性。 本文还与现有的疲劳寿命预测方法进行了横向比较，说明其有独到的优点。更多还原

【Abstract】 In this dissertation, the fact that the concepts of tangent modulus factor (φ₁,), proportional limit law （PLL） and strength utilization ratio function （SURF） in the combined theory of strength and stability （CTSS） are the extension of concerned concepts in elastic mechanics is illustrated. These concepts can be applied not only in strength theory but also in stability theory.By using strain energy theory, tangent modulus theory is farther discussed and applied, and the combined theory of strength and stability is improved.The approach to apply the combined theory of strength and stability into fatigue analysis is discussed. According to the relationship between material fatigue performance curve and concerned parameters in fracture mechanics, the relationship between fatigue life and crack half length is obtained, that is equivalent crack length of fatigue life. The function relationships between these two aspects are constructed. The experiment data show that this method can express the same character of fatigue life of all kinds of materials and experiment data acquired from different materials can be used each other. That is meaningful.The existed material fatigue performance test curves are dealt with and analyzed, and the non-dimensional stress-strain curve, tangent modulus factor curve and fatigue life curve are drawn based on the experiment data, and these three non-dimensional parameter curves are used to find the inherent rules that the test curves can be replaced each other to some extent. It can be concluded that if the common character and system error of these materials are found, the test curve of a certain material can be used for reference by another material. This is a simple approach about fatigue life estimate and is engineering practical.At the same time, the approach proposed in this thesis is compared withexisted approaches to estimate fatigue life, and the result shows its unique advantages.更多还原