I turns out to be that the position and degree of damage can not be well detected only by eigenfrequency , while only can detect if the damage has appeared . however , severe damage can be diagnosed if the modal shape and natural period are used 利用以上指标对试验构件的损伤进行识别与定位,研究结果表明,仅凭获取的固有频率不能准确判断结构构件的损伤状态及损伤位置,只能初步判断结构中是否出现损伤。
Two models for dynamic damage evolution of materials in general anisotropic damage state were presented ; the first one was based on power function of the effective equivalent stress and the second on the damage strain energy release rate 研究了工程材料在动力载荷下损伤演化的计算模型，提出了一般材料在各向异性损伤状态下的两种动力损伤模型。第一种以有效应力的等效值的幂函数为基础，第二种以损伤应变能释放率为基础。
These relations are ambiguous and are n ' t able to be formulated today . making use of the artifical neural network ( ann ) , those relations between dsps and damage / health status are ascertained approximatively . by monitoring these dsps in structures , healthy status could be supervised 这些标识量和结构的损伤状态存在着确定的但是目前无法解析出来的映射关系，通过神经网络可以较准确地来拟合这种标识量和损伤失效状态之间的关联。
With the variation rate of the first mode as a signature for damage detection , it is shown that the variation rate of the first mode not only is sensitive to the damage location and the extent , but also obeys the law of superposition 取结构的一阶振型变化率作为损伤诊断标识量，计算分析显示该标识量不仅对结构的损伤位置以及损伤程度敏感，而且在多位置损伤状态下结构的损伤位置和损伤程度是各单位置损伤状态下结构的损伤位置以及损伤程度的叠加。
By adjusting model parameter , we will build up the dynamic analysis model . thus we will make certain the damage of huqiu pagoda , provide the reference for its earthquake - resistance appraise and reliability assessment , even for other similar ancient buildings " research further 通过拟合模型参数，建立反映虎丘塔动力特性的三维实体模型，为进一步确定虎丘塔的损伤状态，对虎丘塔进行抗震鉴定、可靠性鉴定提供依据，同时也为其它同类古建筑的研究提供参考。
Influence of the temperature field and stress field is ignored but some other factors are considered such as temperature difference between the surface and inside of the concrete , circumstance temperature , work sequence , shaping period , elasticity modulus , the volume etc . and the emulation technology is applied to calculating the construction of the concrete 运用仿真技术对大体积混凝土结构进行了不考虑损伤状态下的温度场及应力场的仿真计算。计算过程中综合考虑了混凝土结构内部温度的变化，环境温度的变化，施工顺序，浇筑时间以及材料弹性模量的变化，徐变特征，自身体积等因素，同时指出了仿真计算中存在的问题与不足之处。
Based on the study of strength degradation of material in the fatigue process , a strength degradation model is proposed . a stochastic differential equation , which controls strength degradation , is obtained from the model randomized by markov process . by using the theory of stochastic , the distributions of residual strength at any given lifetime and lifetime of any given residual strength are attained . under a few suitable hypotheses , inverse gaussian distribution of fatigue life is derived , and verified by means of experimental data . the result shows that the model and the method are reasonable 在研究疲劳过程中材料强度退化规律的基础上,建立了一个强度退化模型.对其进行随机化处理,得到控制强度退化过程的随机微分方程.在一定假设条件下,获得了剩余强度概率密度函数的封闭解,并推导出疲劳寿命的反高斯分布形式.给出一种考虑损伤状态对随机涨落影响的近似处理方法.与试验数据的比较结果表明,本文的模型和方法是合理的
The precise fe model was used to predict the factors of load - carrying capacity of the controlled sections of the box - girder , by selecting some important factors which can affect the load - carrying capacity , such as the area of cables , stiffness of expanding joints , elastic modulus of concrete , and the amount of living load , to simulate the several possible damages of the bridge in service in the future （ 3 ）该桥在运营四年后，索力、挠度、应力与主塔偏位都在设计允许的范围内，大桥依然具备通行设计汽车荷载的能力。 （ 4 ）对该桥承载力的预测分析表明：在所分析的可能损伤状态下，拉索具有足够的安全系数，损伤对控制截面的承载能力系数影响较大。
Abstract : based on the study of strength degradation of material in the fatigue process , a strength degradation model is proposed . a stochastic differential equation , which controls strength degradation , is obtained from the model randomized by markov process . by using the theory of stochastic , the distributions of residual strength at any given lifetime and lifetime of any given residual strength are attained . under a few suitable hypotheses , inverse gaussian distribution of fatigue life is derived , and verified by means of experimental data . the result shows that the model and the method are reasonable 文摘:在研究疲劳过程中材料强度退化规律的基础上,建立了一个强度退化模型.对其进行随机化处理,得到控制强度退化过程的随机微分方程.在一定假设条件下,获得了剩余强度概率密度函数的封闭解,并推导出疲劳寿命的反高斯分布形式.给出一种考虑损伤状态对随机涨落影响的近似处理方法.与试验数据的比较结果表明,本文的模型和方法是合理的
