In order to better meet the objective requirements of the use safety of the high-rise glulam building floor structure and the living comfort of the residents,the transient excitation,environmental excitation and frequ...In order to better meet the objective requirements of the use safety of the high-rise glulam building floor structure and the living comfort of the residents,the transient excitation,environmental excitation and frequency spectrum identification methods were used to carry out experimental modal test in-site on the three rooms numbered A,B and C of the same glulam structural building.The three rooms have different functions,different floor sizes and different floor supporting structures.The research results have shown that the first-order bending frequency of the floor structure of Room A is 27.50 Hz,the transverse second-order bending frequency is 34.75 Hz,the longitudinal second-order bending frequency is 53.25 Hz,and the first-order torsional frequency is 56.25 Hz.The reinforced wooden beam at the bottom of the floor of Room A increases the transverse stiffness of the floor structure,but does not offset the anisotropy caused by the longitudinally installed glulam floors.The fundamental frequency values of the floor structures of the three rooms numbered A,B,and C are 27.5,13 and 18 Hz,respectively.This has a relatively high innovation and reference significance for integrating the theory of structural dynamic characteristics with the dynamic testing technology,improving the design level of high-rise glulam structure buildings,and improving the living comfort of residents.展开更多
Structural problems associated with excessive vibration of building floor systems when subjected to human rhythmic activities have been frequent.In this context,this research work aims to develop an analysis methodolo...Structural problems associated with excessive vibration of building floor systems when subjected to human rhythmic activities have been frequent.In this context,this research work aims to develop an analysis methodology to evaluate the human comfort and assess the fatigue performance of steel-concrete composite floors when subjected to human rhythmic activities(aerobics).The investigated structural model corresponds to a steel-concrete floor with dimensions of 10 m×10 m and a total area of 100 m^(2).The numerical model developed for the dynamic analysis of the floor adopted the usual mesh refinement techniques present in finite element method(FEM)simulations implemented in the ANSYS program.The investigated floor dynamic response was calculated through the consideration of people practicing rhythmic activities on the structure,in order to verify the occurrence of excessive vibration and to assess the human comfort.The fatigue assessment is based on a linear cumulative damage rule through the use of the Rainflow-counting algorithm and S-N curves from traditional design codes.The results indicated that,in several analysed situations,the investigated floor presents excessive vibration and user’s discomfort.On the other hand,the structure service life values were higher than those proposed by the design codes,ensuring that the members,connections and joints will not fail by fatigue cracking.展开更多
The current steel-concrete composite floors design might be susceptible to the resonance phenomenon, causing undesirable vibrations in the frequency range that is the most noticeable to humans, i.e., 4 Hz to 8 Hz. Thi...The current steel-concrete composite floors design might be susceptible to the resonance phenomenon, causing undesirable vibrations in the frequency range that is the most noticeable to humans, i.e., 4 Hz to 8 Hz. This way, the main objective of this work is to investigate the dynamic structural behaviour of a steel-concrete composite multi-storey building when subjected to human rhythmic activities （aerobics）. The studied structural model represents a typical interior floor bay of a commercial building used for gym and is composed by three floor levels spanning 20 m by 20 m, with a total area of 3×400 m2. An extensive parametric study was developed aiming to obtain the peak accelerations, RMS （root mean square） accelerations and VDV （vibration dose value） values, based on two different mathematical formulations. The human comfort of the building was analysed and the vibration transmissibility related to the steel columns was verified. Based on the found results, the investigated structural model presented high vibration levels that compromise the human comfort.展开更多
The increasing strength of new structural materials and the span of new structures, accompanied by aesthetic requirements for greater slenderness, are resulting in more applications of long-span structures. In this pa...The increasing strength of new structural materials and the span of new structures, accompanied by aesthetic requirements for greater slenderness, are resulting in more applications of long-span structures. In this paper, serviceability control technology and its design theory are studied. First, a novel tuned mass damper （TMD） with controllable stiffness is developed. Second, methods for modeling human-induced loads are proposed, including standing up, walking, jumping and running, and an analysis method for long-span floor response is proposed based on a finite element model. Third, a design method for long-span floors installed with a multiple TMD （MTMD） system considering human comfort is introduced, largely based on a study of existing literature. Finally, a design, analysis and field test is conducted using several large scale buildings in China including the Beijing Olympic Park National Conference Center, Changsha New Railway Station and the Xi＇an Northern Railway Station. The analytical and field test results show that the MTMD system designed using the proposed method is capable of effectively mitigating the vertical vibration of long-span floor structures. The study presented in this paper provides an important reference for the analysis of vibration serviceability of similar long-span floors and design of control system for these structures.展开更多
大跨曲线钢桁梁人行桥竖向、横向和扭转振型耦合强,人致振动舒适度评价和减振控制难度大。以湖南省长沙市浏阳河一主跨为120 m的曲线双层桥面三跨连续钢桁梁桥—汉桥为工程背景,通过理论分析和人群激励现场动力试验,识别桥梁固有模态参...大跨曲线钢桁梁人行桥竖向、横向和扭转振型耦合强,人致振动舒适度评价和减振控制难度大。以湖南省长沙市浏阳河一主跨为120 m的曲线双层桥面三跨连续钢桁梁桥—汉桥为工程背景,通过理论分析和人群激励现场动力试验,识别桥梁固有模态参数,评价人致振动舒适性,优化设计调谐质量阻尼器(Tuned Mass Damper,TMD)并评价TMD的减振效果。研究表明:因桥梁第一阶竖弯模态和第一阶扭转模态的阻尼比仅为0.23%和0.3%,人致振动加速度不满足舒适性要求;采用竖向TMD进行竖弯模态和扭转模态的减振控制,减振后的桥梁满足舒适性要求。展开更多
文摘In order to better meet the objective requirements of the use safety of the high-rise glulam building floor structure and the living comfort of the residents,the transient excitation,environmental excitation and frequency spectrum identification methods were used to carry out experimental modal test in-site on the three rooms numbered A,B and C of the same glulam structural building.The three rooms have different functions,different floor sizes and different floor supporting structures.The research results have shown that the first-order bending frequency of the floor structure of Room A is 27.50 Hz,the transverse second-order bending frequency is 34.75 Hz,the longitudinal second-order bending frequency is 53.25 Hz,and the first-order torsional frequency is 56.25 Hz.The reinforced wooden beam at the bottom of the floor of Room A increases the transverse stiffness of the floor structure,but does not offset the anisotropy caused by the longitudinally installed glulam floors.The fundamental frequency values of the floor structures of the three rooms numbered A,B,and C are 27.5,13 and 18 Hz,respectively.This has a relatively high innovation and reference significance for integrating the theory of structural dynamic characteristics with the dynamic testing technology,improving the design level of high-rise glulam structure buildings,and improving the living comfort of residents.
基金the support for this work provided by the Brazilian Science Foundations:CAPES,CNPq and FAPERJ.
文摘Structural problems associated with excessive vibration of building floor systems when subjected to human rhythmic activities have been frequent.In this context,this research work aims to develop an analysis methodology to evaluate the human comfort and assess the fatigue performance of steel-concrete composite floors when subjected to human rhythmic activities(aerobics).The investigated structural model corresponds to a steel-concrete floor with dimensions of 10 m×10 m and a total area of 100 m^(2).The numerical model developed for the dynamic analysis of the floor adopted the usual mesh refinement techniques present in finite element method(FEM)simulations implemented in the ANSYS program.The investigated floor dynamic response was calculated through the consideration of people practicing rhythmic activities on the structure,in order to verify the occurrence of excessive vibration and to assess the human comfort.The fatigue assessment is based on a linear cumulative damage rule through the use of the Rainflow-counting algorithm and S-N curves from traditional design codes.The results indicated that,in several analysed situations,the investigated floor presents excessive vibration and user’s discomfort.On the other hand,the structure service life values were higher than those proposed by the design codes,ensuring that the members,connections and joints will not fail by fatigue cracking.
文摘The current steel-concrete composite floors design might be susceptible to the resonance phenomenon, causing undesirable vibrations in the frequency range that is the most noticeable to humans, i.e., 4 Hz to 8 Hz. This way, the main objective of this work is to investigate the dynamic structural behaviour of a steel-concrete composite multi-storey building when subjected to human rhythmic activities （aerobics）. The studied structural model represents a typical interior floor bay of a commercial building used for gym and is composed by three floor levels spanning 20 m by 20 m, with a total area of 3×400 m2. An extensive parametric study was developed aiming to obtain the peak accelerations, RMS （root mean square） accelerations and VDV （vibration dose value） values, based on two different mathematical formulations. The human comfort of the building was analysed and the vibration transmissibility related to the steel columns was verified. Based on the found results, the investigated structural model presented high vibration levels that compromise the human comfort.
基金National Natural Science Foundation of China Under Grant No.51178100Foundation of the Priority Sciences Development Program of Higher Education Institutions of Jiangsu Province Under Grant No.1105007001+1 种基金Teaching and Research Foundation for Excellent Young Teachers of Southeast University Under Grant No.3205001205Scientific Research Foundation the Scientific Research Foundation of Graduate School of Southeast University Under Grant No.YBJJ1006
文摘The increasing strength of new structural materials and the span of new structures, accompanied by aesthetic requirements for greater slenderness, are resulting in more applications of long-span structures. In this paper, serviceability control technology and its design theory are studied. First, a novel tuned mass damper （TMD） with controllable stiffness is developed. Second, methods for modeling human-induced loads are proposed, including standing up, walking, jumping and running, and an analysis method for long-span floor response is proposed based on a finite element model. Third, a design method for long-span floors installed with a multiple TMD （MTMD） system considering human comfort is introduced, largely based on a study of existing literature. Finally, a design, analysis and field test is conducted using several large scale buildings in China including the Beijing Olympic Park National Conference Center, Changsha New Railway Station and the Xi＇an Northern Railway Station. The analytical and field test results show that the MTMD system designed using the proposed method is capable of effectively mitigating the vertical vibration of long-span floor structures. The study presented in this paper provides an important reference for the analysis of vibration serviceability of similar long-span floors and design of control system for these structures.
文摘大跨曲线钢桁梁人行桥竖向、横向和扭转振型耦合强,人致振动舒适度评价和减振控制难度大。以湖南省长沙市浏阳河一主跨为120 m的曲线双层桥面三跨连续钢桁梁桥—汉桥为工程背景,通过理论分析和人群激励现场动力试验,识别桥梁固有模态参数,评价人致振动舒适性,优化设计调谐质量阻尼器(Tuned Mass Damper,TMD)并评价TMD的减振效果。研究表明:因桥梁第一阶竖弯模态和第一阶扭转模态的阻尼比仅为0.23%和0.3%,人致振动加速度不满足舒适性要求;采用竖向TMD进行竖弯模态和扭转模态的减振控制,减振后的桥梁满足舒适性要求。
