On Hysteretic Restoring Force in Damping Identification of Structures in Elasto-plastic Range

Based on the data of inelastic dynamic-static comparison tests of three pairs of SDOF small steel frames, the problem of hysteretic restoring force in damping identification of structures in elasto-plastic range is investigated.     

On Determinative Parameters of SDOF Systems in Elasto- plastic Earthquake Response

Parameters dominating elasto- plastic earthquake response of SDOF systems,relation between ground motion amplitude and elasto- plastic response of SDOF systems are presented in this paper.     

Earthquake Response Properties of the Support Structure of Large Cross Section Tunnel

The response properties of displacement and stress of tunnel support structure are discussed in detail under the action of horizontal earthquake acceleration(Ya),longitudinal earthquake acceleration(Za) and horizontal-longitudinal earthquake acceleration(YZa).This discussion is based on an analysis of the surrounding rock-support structure-earthquake interaction,adoption of an ADINA nonlinear finite element and construction mechanics,and transient dynamic time domain analysis of a large cross section tunnel.Results of analysis show that:(1) Horizontal earthquake acceleration has important influence on horizontal displacement,maximum principal stress,acceleration and velocity.(2) Longitudinal earthquake acceleration has important influence on longitudinal displacement,effective stress,maximum and minimum principal stress,maximum shear stress,acceleration and velocity.(3) When Ya=0.191g and 0.440g or Za=0.141g and their combined action,the initial support of tunnel would be damaged and the local lining would have partial damage.(4) When Ya=0.440g or Za=0.326g and their combined action,the lining of tunnel would be damaged.(5) When Ya=0.880g or l Za=0.652g,the support structure of tunnel would have severe damage.     

Distribution of Earthquake Total Input Energy of Structures

This paper discusses the distribution regularity of earthquake total input energy of structures between hysteretic energy and damping energy and their influencing factors taking account of various factors.The results can serve as the basis for the energy method of aseismic structural design and energy analysis in the study of damage criteria.     

关中西部农村居民地震灾害认知与响应研究-以宝鸡市陈仓区为例

为制定农村防震减灾相关政策并为其提供实证依据。采用问卷调查和比较分析的方法,对宝鸡市陈仓区农村居民的地震灾害认知与响应进行调查研究。结果表明：(1)居民地震灾害知识的准确性和深度不够,防震减灾技能掌握不足;(2)居民有一定的自救互救意识,但主动性和组织性较差,地震谣言辨别能力不强;(3)居民地震灾害认知与响应的总体水平不够理想,其中防震减灾技能最差,自救互救实况最好。表明开展地震灾害知识普及、防震减灾技能培训和地震信息甄别工作是增强农村地区防震减灾综合能力的有效途径。     

Effects of Response Spectra Dispersion of Earthquake Ground Motions on Probabilistic Seismic Demand Assessment of Bridge Structures

A three-span regular continuous RC girder highway bridge and two bins of real accelerograms were selected for incremental dynamic analysis to study the correlation of the dispersions of response spectra of earthquake ground motions and probabilistic seismic demand assessments of bridge structures. It is found that the dispersions of seismic demands are closely related to the dispersions of response spectra of selected ground motions. The rational selection of real earthquake ground motions to be rationally chosen for dynamic analysis can make the probability distribution of seismic demands in accordance with the real situation and improve the computational precision and efficiency of the probabilistic seismic demand assessment and fragility curve for performance-based earthquake engineering and seismic design of bridges based on probability theory.     

Analysis of Structure with Tuned Mass Damper under Earthquake

The analysis of vibration response of structure with TMD is carried out under earthquake ,considering the ground-structure interaction. The varying rule of square difference of displacement of structure with the TMD on or off by changing the first inherent frequency is also presented .It has been proved by comparing and analyzing that a TMDstructure with optimum parameters can efficiently reduce the vibration of structure under strong wind and earthquake,when the main frequency of the ground motion is within the range of TMD vibration reducing frequency.     

Axial Force Stiffness Interaction in Seismic Analysis of RC Double Column Bridges

Earthquake induced dynamic axial force in reinforced concrete (RC) bridge bent columns will not only change the yield strength of the columns but also change their stiffness, which is seldom considered by the common lumped plasticity line model. Based on the fiber element model results that taking into account the influence of dynamic axial force on strength and stiffness simultaneously, the axial force stiffness interaction effect on the seismic responses of RC double column bridges was analyzed. The results show that, axial force stiffness interaction has a large effect on the seismic responses of the double column bridge in the elastic range, and it does not alter the ultimate capacity of the columns. Since the stiffness of the columns under compression and tension dynamic axial forces offset each other, the global displacement of bridge bent with equal columns is relatively unaffected by the axial force stiffness interaction, however, the differences of the column member forces are manifest. For the short column controls the global stiffness, the axial force stiffness interaction has significant influences on both the global displacement and member force responses. The influences become larger as the irregularity of the bridge bent increases, so the interaction between axial force and member stiffness should be sufficiently considered in seismic analyses.     

Test of Frequency Response Characteristics of Acupuncture Points in Human Ears and Correlation Analysis between the Characteristics and the Human Diseases

This paper presents a new disease diagnosis approach with a woundless testingtechnique.We fetch the data from acupoints in human ears,and then analyse their statistic and frequency response features by computsr in order to find out their characteristic functions.By studingthe correlation between these functions and human diseases,we can diagnose which disease the patient has been suffered.     

Discussion on Several Problems for Application of Modulated ARMA Model in Simulation of Earthquake Waves

In this paper, the application of modulated ARMA model in simulation of artificial earthquake waves is discussed on the several aspects such as determination of the ARMA model orders, determination of the ARMA model parameters and influence of the initial random series. It is shown from the calculation that the influence of the intensity envelop function on the frequency characteristic of the modulated ARMA model is acceptable and the modulated ARMA model is still an efficient alternative method to generate artificial earthquake wave in practice.     

基于岭回归模型的农村剩余劳动力转移影响因素分析

为更好的解释农村剩余劳动力转移的影响因素,在国内外农村剩余劳动力研究的基础上,笔者运用定性和定量相结合的分析方法进行分析。为避免多重共线性在模型中的影响,采用岭回归模型对相应影响变量进行分析。通过模型综合分析,验证了影响中国农村剩余劳动力转移的推动因素和制约因素。同时提出发展区域经济,提高农民收入;推进城镇化进程,拓宽农民就业渠道;促进二、三产业发展转型与加强农民专业培训齐头并进;深化以户籍制度为中心的制度变革等4项政策建议。     

Point Force Model of Smart Structure Piezoelectric Actuator With Paste Layer

In the smart bar-beam structure with piezoelectric strain actuator active control function to vibration, the thickness effect of paste layer is considered and strain is assumed linear distribution along the thickness direction of each layer. The piezoelectric actuator point force model of Crawley and Luis is refined, a more general point force model is established to the smart beam with strain actuator. Point force model calculation formula is educed to smart beam with two-side symmetry paste actuator or one-side paste actuator. The computer simulation is done and the result reveals modified point model is right. The modified model is more common, as is important to design piezoelectric smart structure.     

广西柑橘气候适宜度模型

研究旨在建立广西温度、降水、日照和综合要素的日尺度适宜度模型,应用于广西柑橘气候适宜度等级分类,以及历年气候适宜度时空分布特征进行分析.利用广西87个国家自动气象站1961-2018年逐日气象资料和柑橘生长气候习性,采用模糊数学方法建立模型,并利用典型年份、阶段异常天气进行模型验证.结果 表明,模型的逐日气象要素回归拟...     

Analysis on Wind-induced Dynamic Response of Arched Corrugated Metal Roof

It is generally considered that the seismic response of arched corrugated metal roof is not the control factor of structure design because of its light dead weight, but the wind-induced dynamic response on the structure is significant, so more attention must be paid to it. First, the wind simulation of the structure by AR model is carried out. Then, the TRANS method in the ANSYS is used to calculate the dynamic responses in time domain to compare the results with those in frequency domain in order to verify the validity of the two methods.     

Curvature Force Method for Nonlinear Analysis of Prestressed Concrete Frame

In this paper, based on the structure characters and load applying means, a method called as curvature force method is put forward and proved in the nonlinear analysis of bonded prestressed concrete frame. Based on the nonlinear program, the simulation calculation was carried out on test results of two prestressed concrete frames by this method. The results from calculation are identical with the experiment ones. So it may be added to the methods for the nonlinear analysis of prestressed concrete frame.     

Pressure-Dependent Analysis of Water Supply Network Damaged by Earthquake Based on Emitter Model

When the water supply network suffered earthquake damages, pipeline leaks and bursts may occur. In the period in post-earthquake emergency rescue and repair, the network is supplying water with additional outflow of damages (leaks and breaks), which result in pressure deficient. According to the frictional head loss along the break pipeline, a model with additional emitter at the endpoint of the disconnect pipeline was proposed to simulate the break, which simplifies the modeling of breaks. The pressure-dependent demand relationship was adopted in the process of pressure-deficient hydraulic simulation to avoid node negative pressure. Meanwhile a backtracking and line search procedure was utilized to control the iteration step of pipeline network nonlinear equations, which ensure the global convergence of the hydraulic simulation. The effectiveness of the proposed method was verified by a case study.     

枸杞不同品系的光合特性及光响应模型拟合研究

为深入了解枸杞光合特性,探讨不同光响应模型对枸杞光合作用的实用性,以期为枸杞新品种的选育提供理论依据。以‘14-Z44’、‘14-2-3-20’、‘宁杞1号’为研究对象,比较3个品种（系）间的叶片形态生理及光合特性指标,利用不同光响应模型分别对3个品种（系）叶片的光合光响应曲线进行拟合。结果表明,‘14-2-3-20’叶片形态特征和生物量与‘宁杞1号’有显著差异,叶厚度、比叶重无差异。与实测值相比,直角双曲线模型、非直角双曲线模型拟合的各测量点的光合速率最接近实测值,但光合参数值与实测值差异较大,直角双曲线修正模型拟合的光响应曲线、光合参数均接近实测值,并有光抑制现象。与‘宁杞1号’相比,‘14-2-3-20’、‘14-Z44’的LCP、LSP、Rd均较低,α较高,‘14-2-3-20’的Pn_max最高。综合分析得出,直角双曲线修正模型较适用于拟合枸杞光响应曲线,‘14-2-3-20’弱光利用能力强,强光下光合能力也高,不易出现光抑制现象,在选育丰产品种方面有潜在的价值。     

Analysis of the Total Energy and Its Influencing Factors for Seismic Structures

In this paper, the total input earthquake energy and influencing effects for shear type,shear-bending type, bending type aseismic structures of the single freedom system and multiple freedom elastic-plastic system are analyzed by synthesizing various effects and employing the timehistory analysis method. Based on the analysis results, the total input earthquake energy spectrum is presented.The simplified methods for analyzing the total input energy of multiple freedom elastic-plastic systems are proposed to provide some basis for developing aseismic structure design method and Double-Failure Criteria.     

Analysis on Characteristics and Driving Force of Urbanization of Longgang District,Shenzhen

Longgang District is an important industrial park for carving out a business in Shenzhen City. The author thinks that the rural urbanization course of Longgang District is obvious in phases. At present, it is in fast development period. The basic characteristic of the rural urbanization in Longgang District is as follows: 1.The raw and processed materials come from out and the products go out of the district; 2.The urbanization standard of the west of Longgang District is better than that of the east. According to the analysis on economic growth, economic type and industrial structure during different years, the driving force and the differentiation law of urbanization in Longgang District is put forward.