Preliminary Study On The Scheme Design Of Measurement Standard For Bridge Cable Force Dynamic Measuring Instrument

Cable force is an important influence quantity during the whole life of bridge,which is measured by cable force dynamic measuring instrument,but its accuracy is questionable.In this paper,based on the cable force dynamic measuring method and metrology,scheme design of measurement standard for cable force dynamic measuring instrument are preliminarily studied.Main work are in the following areas:(1)Surveys for cable force dynamic measuring method and metrology.The theory of cable force dynamic measuring instrument and its theoretical assumptions are studied,the development trendency of Chinese metrology are analysed,and the current situation and its problem for transport industry instruments when they meet metrology are obtained.So,cable force dynamic measuring instrument also need to fill the gaps in its measurement standards and quantity transmission / traceability.(2)The theoretical basis of dynamic cable force measuring method are analyzed and summarized.Under practical conditions,it is need to consider the cable sag,flexural rigidity and boundary conditions.Based on the two dimensionless parameters?2? ?,which reflect sag and flexural rigidity,the research methods for influencing factors are analyzed,and the sectional explicit formulation of cable force measuring method are summed up.(3)The theoretical basis of metrology are analyzed and summarized,including the composition of measurement system,content of quantity transmission / traceability system,the importance of establishing measurement standards.The core study of this paper is calibration.The measurement uncertainty is divided into three categories,and its evaluation method are studied.Through examples,the paper analyzes the connotation of measurement standard system as its core factors are measurement standard device and measurement calibration scheme.(4)The core factors of cable force dynamic measuring instrument are analyzed,the current situation of cable force dynamic measuring instrument are surveyed,the existing technical conditions of cable force dynamic measuring instrument for its measurement standard are analyzed.Cable force dynamic measuring instrument standard system should include the measurement standard device,cable force measurement instrument calibration specification and device manufacturing standard.The technical route ismade,firstly conduct cable classification,secondly design measurement standard device,and then compile calibration scheme.(5)On the level of metrology,the cable is divided into short cable,long cable and middle cable.The classification criteria is given,and full scale test of cable is done.Through ANSYS and catenary statics analysis,the specific parameters requirements for this criteria are studied.Then,specific parameters of the three kinds of cable for measurement standard device are selected.(6)The measurement standard device of cable force dynamic measuring instrument is designed.Based on the device,the plane of calibration scheme for cable force dynamic measuring instrument is carried out.The calibration requirements are cleared,and its calibration contents are given,including metrological characteristics,calibration conditions,calibration method,calibration content,calibration method,calibration results as well as assessment method for the uncertainty of the results.