Research On The Effect Of Human-induced Load On Vertical Comfort Of Large-span Prestressed Secondary Beam Floor Structure Considering Floor Decoration

With the application of lightweight and high-strength materials to building structures,more and more large-span lightweight floor covering systems are used in public buildings that require large space functional requirements,such as shopping malls,stadiums,and office buildings.light weight,and material saving,but also because of the softer structure,it is easy to cause comfort problems under human-induced loads.Based on the background of Building 3rd(Gymnasium)of the primary school construction project in the core area of Xincheng District,Tongliang District,Chongqing,this paper focuses on the vertical vibration control of the large-span prestressed secondary beam floor.The main research work and results of this article are:1 Considering the influence of decoration surface layer on vertical comfort,the ANSYS three-dimensional solid finite element model is established.The secondary beam height,floor thickness,decoration surface,flat beam floor thickness and dynamic elastic modulus are the influencing factors.The 36 floor plans that were formed were used for modal analysis and 12 floor plans for dynamic analysis.Analyze the influence of various factors on the floor natural vibration frequency and peak acceleration.2 The results of modal analysis show that the decoration surface of the wooden floor as a non-structural component will affect the rigidity and quality of the structural system to a certain extent,thereby affecting the natural frequency of the structure.As the thickness of the decoration surface increases,the base of the floor cover The frequency gradually increases,but the amplitude is small;as the height of the secondary beam increases,the natural frequency of the floor increases significantly,and the increase ratio of the fundamental frequency to the height of the secondary beam is about0.55;as the thickness of the floor increases,the natural vibration of the floor The frequency is slightly reduced;the increase in the basic frequency of the floor with a flat beam compared to the floor without a floor is more than 20%.With the increase of the thickness of the floor,the frequency of the floor is increased by a small amount;when the dynamic elastic modulus is considered,The increase ratio of elastic modulus is about 0.4.3 The dynamic analysis results show that the change of the damping ratio of the floor caused by the decoration surface layer has a greater impact on the acceleration than the acceleration of the stiffness and mass of the floor caused by the change,but neither can be ignored.As the thickness of the floor increases,the floor The greater the peak vibration acceleration of the cover decreases;the addition of a flat beam bottom plate can significantly reduce the peak vibration of the floor.Continue to increase the thickness of the bottom plate to reduce the acceleration,but the amplitude is smaller;increasing the secondary beam height can effectively reduce the peak vibration of the floor;Increasing the floor thickness can reduce the peak vibration acceleration of the floor,but the amplitude is small;increasing the elastic modulus does not play a beneficial role in the floor vibration response when the most unfavorable working condition of the three-way resonance occurs.Peak acceleration It rises slightly,and the peak acceleration can be reduced under non-resonant conditions.4 The vibration response of the floor caused by jumping excitation is much larger than that of the floor caused by walking excitation,which is 3.6 times on average.5 The vertical vibration response of the floor under the uniform load of multiple people walking and jumping simultaneously was studied.The analysis results show that the influencing factors under the load of multiple persons and the single person are consistent with their corresponding influencing rules,and the corresponding reduction coefficients for simultaneous movement of multiple persons are proposed.For the simultaneous movement of four persons,1.0 is adopted;Take 0.9.6 According to the peak acceleration descent rate and the ratio of the descent rate to the various factors,the structural arrangement sequence under the condition of comfort is proposed: adding flat beam bottom plate-increasing beam height-increasing bottom floor thickness-increasing plate thickness,and according to the corresponding ratio obtained in this article as the optimized recommended value.