The concrete hydration heat release process of the base plate is monitored using Roman optical time domain reflectometry（ROTDR） sensing sensors. The monitoring data shows that the internal maximum temperature of the...The concrete hydration heat release process of the base plate is monitored using Roman optical time domain reflectometry（ROTDR） sensing sensors. The monitoring data shows that the internal maximum temperature of the base plate is about 54 ℃ after the concrete was cured for 120 h. The fiber Bragg grating （FBG） temperature sensors are adopted to measure the surface temperature of the concrete and the temperature results are used to compensate the data measured by the pulse-prepump Brillouin optical time-domain analyzer （PPP-BOTDA） to obtain the real concrete surface strain of the base plate. The monitoring data is analyzed to obtain a clear understanding of the strain state of the base plate under the effect of concrete hydration heat release. The monitoring results demonstrate the potential of distributed optical fibre sensing techniques as a powerful tool in real-time construction monitoring, and also provide an important insight into the design, construction and maintenance of large hydraulic structures.展开更多
The electromagnetic balance head is used for balancing the electric spindle. This paper analyzes the internal structure of the electromagnetic balance head and introduces the structure of the counterweight plate and t...The electromagnetic balance head is used for balancing the electric spindle. This paper analyzes the internal structure of the electromagnetic balance head and introduces the structure of the counterweight plate and the range of the balance in the moving ring.The principle of how the electromagnetic field generated by the static coil acts on the moving ring is also investigated. The model is built in Ansoft Maxwell and the excitation parameters and boundary conditions are set up. Through the analysis of the magnetic field generated by the static coil in the position of the moving ring, it is verified that the static loop coil can drive the counterweight plate.展开更多
基金The National Key Technology R&D Program during the 12th Five-Year Plan Period(No.2012BAK10B05)the State Key Program of National Natural Science of China(No.41427801)
文摘The concrete hydration heat release process of the base plate is monitored using Roman optical time domain reflectometry（ROTDR） sensing sensors. The monitoring data shows that the internal maximum temperature of the base plate is about 54 ℃ after the concrete was cured for 120 h. The fiber Bragg grating （FBG） temperature sensors are adopted to measure the surface temperature of the concrete and the temperature results are used to compensate the data measured by the pulse-prepump Brillouin optical time-domain analyzer （PPP-BOTDA） to obtain the real concrete surface strain of the base plate. The monitoring data is analyzed to obtain a clear understanding of the strain state of the base plate under the effect of concrete hydration heat release. The monitoring results demonstrate the potential of distributed optical fibre sensing techniques as a powerful tool in real-time construction monitoring, and also provide an important insight into the design, construction and maintenance of large hydraulic structures.
基金Supported by National Natural Science Foundation of China(61370088)National Special Project of International Cooperation in Science and Technology(2014DFB10060)
文摘The electromagnetic balance head is used for balancing the electric spindle. This paper analyzes the internal structure of the electromagnetic balance head and introduces the structure of the counterweight plate and the range of the balance in the moving ring.The principle of how the electromagnetic field generated by the static coil acts on the moving ring is also investigated. The model is built in Ansoft Maxwell and the excitation parameters and boundary conditions are set up. Through the analysis of the magnetic field generated by the static coil in the position of the moving ring, it is verified that the static loop coil can drive the counterweight plate.
