欢迎您！东篱公司
退出
-
申报数据库
-
立项数据库
-
成果数据库
-
项目获奖数据库
中文摘要：
首先介绍加卸载响应比的2个基本参量，并从损伤力学的基本理论出发，引入损伤变量，结合加卸载响应比方法的思想，推导用损伤和应变定义的加卸载响应比，并以Weibull分布作为随机分布函数，建立且分析损伤变量与加卸载响应比之间的联系，并进一步考察Weibull指数对两者关系的影响。然后利用岩石破坏声发射实验的数据，用声发射数密度描述岩石试件的损伤演化过程，并由此根据损伤和应变定义的加卸载响应比，结合实验过程中的损伤和应变，计算花岗岩试件的加卸载响应比曲线，并与用Benioff应变作响应量计算的加卸载响应比曲线进行比较，发现两者具有相当程度的一致性，两者的加卸载响应比值都经历了出现异常→升高到最大值→急剧回落→岩石试件破裂或失稳，这一规律与实际地震震例中加卸载响应比的演化趋势是一致的，同时也说明在实际地震预测中用Benioff应变作为响应量来计算加卸载响应比是合理的。最后介绍意大利那不勒斯大学完成的二层楼房的加卸载实验，且对实验结果进行分析。建立的加卸载响应比与损伤变量的关系，不仅为加卸载响应比用来定量研究脆性介质的损伤程度提供更为坚实的基础，而且也可能为评估大型建筑的损伤和预测工程事故开辟新道路。
英文摘要：
Two basic parameters of load/unload response ratio（LURR） are introduced firstly; and the new definition of LURR is conducted using damage and strain of materials as response based on the theory of damage mechanics and the idea of LURR. Furthermore, the relation between LURR and damage variable（D） is set up and analyzed with Weibull distribution as probability distribution function; and the effect of Weibull exponential on the relation is also investigated. Secondly, the process of damage evolution in the rock failure acoustic emission（AE） experiment carried out in 2003 is described with AE number density utilizing the experimental data. The curve of LURR against time defined by damage and strain of the granite specimen is calculated and compared with the one calculated with Benioff strain as response rate. The two curves are quite similar, both LURR values experience the same process, i.e. abnormity appears, LURR values rise to the peak with relatively slow speed and then decrease sharply, rock specimens fail or destabilize quickly, which is consistent with the trend of LURR curves calculated with seismic data and also shows the rationality of LURR defined with Benioff strain as response rate in the actual earthquake prediction. In the end, the loading and unloading experiments on a two-story structure carried out in the University of Naples in Italy are presented; and the experimental data are analyzed using LURR method. In a word, the relation between LURR value and D not only provides more detailed basis to study the damage evolution of a certain kind of brittle materials utilizing LURR method, but also offers a new approach to the health assessment to large-scale structures and prediction of engineering catastrophic failure.
同期刊论文项目
同项目期刊论文
Molecular dynamics study of mechanical behaviour of screw dislocation during cutting with diamond ti
Eigenfrequency Computation of Beam/Plate Carrying Concentrated Mass/Spring and Its Application to Re
Orientation-dependent adhesion strength of a rigid cylinder in non-slipping contact with a transvers
Response to "Comment on 'Deformation mechanisms of face-centeredcubic metal nanowires with twin boun
A simple method to simulate shrinkage-induced cracking in cement-based composites by lattice-type mo
Role of vertical component of surface tension of the droplet on the elastic deformation of PDMS memb
Shape effects on the yield stress and deformation of silicon nanowires: A molecular dynamics simulat
Adsorption of formaldehyde molecule on the intrinsic and Al-doped graphene: A first principle study.
Universal Biot number determining the stress duration and the susceptibility of ceramic cylinders to
An Elasto-plastic Damage Constitutive Theory Based on Pair Functional Potentials and Slip Mechanism,
Trans-scale mechanics – looking for the missing links between continuum and micro/nanoscopic reality
Universal Biot number determining stress duration and susceptibility of ceramic cylinders to quenchi
Determination of plastic properties by instrumented spherical indentation:Expanding cavity model and
A comparative study of Young’s modulus of single-walled carbon nanotube by CPMD, MD, and first princ
Analytical method of predicating the instabilities of a micro arch-shaped beam under electrostatic l
Failure process analysis of cement under explosive loading with a generalized driven nonlinear thres
On the formation of periodic segmentation cracks in a coating plated on a substrate with periodic su
State vector: A new approach to prediction of the failure of brittle heterogeneous media and large e
Study of the damage-induced anisotropy of quasi-brittle materials using the component assembling mod
Comparison between LURR and state vector analysis before strong earthquakes in southern California s
Modified generalized beam lattice model associated with fracture of reinforced fiber/particle compos
Comparison of the quasi-static method and the dynamic method for simulating fracture processes in co
期刊信息
位置：