Research Of Vibration Comfort Of Large Span Stadium Grandstand Based On Annoyance Rate Model

With the progress of the society and technology,the modern constructions,such as stadiums and elevated stations are gradually developing to the tendency of low frequency,large span and being flexible.These tendencies make the structural fundamental frequency and the frequency of activities more and more closer,leading to severe vibrations,which make people feel uncomfortable,even leads to some dangerous events.Therefore,the researchers pay more attention on the research of the influence of people activities upon the structures.On the other hand,with the progress of the material life,the spiritual life needs to be enhanced too.The number of recreational and sports activities,such as concerts and matches are growing,making the demand of stadiums continue to increase.As the structures which is frequently used and where people usually gather around,stadiums' vibration comfort problems are particularly important.Therefore,the research on the comfort problems of the stadium has important significance and value.In this paper,the study of comfort problems uses numerical simulation,field measurement and theoretical analysis.By numerical simulation and measurement,the change rules of dynamic properties of structures which were influened by stationary people and the comfort evaluations could be obtained.Improve the annoyance rate model based on the traditonal annoyance rate model,optimize the design of the structure and then analyses vibration comfort problems corresponding on grandstand structures.To consider evaluating comfort of the grandstand structure by multi-factors,this paper combines Analytic Hierarchy Process(AHP)and Fuzzy Integrated Evaluation method to analyses.The main contents are as follows:1.Establish the finite element model of the stand of Harbin exhibition ceter stadium,use the block Lanczos method for modal analysis and get the frequencies of the model.Then by comparing those with the measurement results,it was found that the errors were within the allowable range,proving the correctness of the model.Act the crowd load on the structure and then the regularities of acceleration response distribution were achieved.By those regularities,the positons of testpoints were ascertained.2.The speed and acceleration time history curves were measured when crowd load acted on the stand structure.Using SSI method to analyses spectrum,the frequencies of the structure of no-load action and crowd load actions were attained.By those data,the change rules of dynamic properties of structurse which were influened by stationary people were obtained.Calculate the different vibration evaluations and then simulation and measurement results were compared to prove the validity and credibility of the measurement.Finally,evaluate the comfort of the stand by different standards and research on the differences of comfort of diverse patamaeters.3.As to the existent annoyance rate models,the improved method was put forward.The biggest differences between those were the optimization of membership functions,using k type parabolic form of membership function instead of trapezoidal type functional form.The k type parabolic form of membership function was proved to be superior to the tradional one.Combining membership degree and the otherness of the feelings of different people,the calculation formulas of annoyance rate and the annoyance rate curves were given.Then cumulative lognormal distribution function curves were used to approximately fit annoyance rate curve,and the fitting results were good.Lastly,verify the correctness of annoyance rate curve.Based on improved annoyance rate model,the design methods of vibration comfort and structure optimization analysis were put forward.After that,a related calculation example was given.Provide a method to evaluate vibration comfort of the stand structure based on the improved annoyance rate model.4.Consider using multi-factors to evaluate the comfort of human body acting on the stand.The multi-factors include vibration,temperature and noise.The AHP method was used to determine weights.The number of questionnaires distributed was 95.Then recycle questionnaires and check the consistency of each questionnaire.Finally the weights of different factors were gotten.By fuzzy comprehensive evaluation method,the calculation formula of comfort evaluation was given,and the benchmark of the quantitative classification of vibration was illustrated.