Development Of A Six Components Strain Gauge Wind Tunnel Balance

Strain balance is a single-component or multi-components strain force transducer,which is the most important device in wind tunnel force measurement test. At present,strain balance has been widely used in all kinds of air dynamic measurement experiment.Compared with the mechanical and piezoelectric balance, strain balance has obvious advantages, its characteristic includes fast dynamic response, low designing and manufacturing cost, small volume, light weight, short development cycle and can adapt to various model supporting ways.From the the wind tunnel balance application background, this paper discussed the principle and the characteristics of strain balances in various structure forms, analyzed the factors which may influence the properties of electrical measurement and the compensation ways. The structure of composite components use three beams, and a novel structure form of axial force element is designed, then set up mathematical model of strain and stress in each components based on mechanics of materials. Solidworks is used for selected structure preliminary modeling and mechanics finite element simulation, analyzed the effective output under the design-load conditions of each component as well as the first-order interference between components, constantly optimize structures’ size according to the results of simulation until meet the design requirements. Then put the optimized structures’ size into the mathematical mode to contrast with results of finite element calculation in order to prove the reliability of the design method.After the structure design, paper introduced the manufacturing of this strain balance, present the static calibration work before wind tunnel test. Made the fabrication drawing at the first step, analyzed the processing characteristics of the high strength steel 00Ni18Co8Mo5 TiAl which adopted in the balance, designed the measurement circuit according to structure styles and strain-models. Then, in view of the strain balance is small volume, structure complexity in addition the high strength characteristics of material adopted, design the specific manufacturing processes. First of all, finish solid solution treatment on blank material, complete all mechanical processing during the condition of solid solution, then complete age hardening, and finished the strain gauge sticking and circuit connection. In the static calibration part,firstly analyzed the calibration principle, loading method and the calculation of corresponding loading force(torque), then elastic angle correction formula and the data processing method are given, finally complete the balance’s use-formula from static calibration data.This strain balance performance prove to be meet the requirements from the calibration assessment at the end of the article.The theoretical research, concrete design,manufacturing and static calibration of this paper has certain guiding function for the research and development of similar strain force measuring devices.