Dynamic Stress Measurement Method in Concrete Based on Matching Error Analysis and Correction

Accurate measurement of dynamic stresses in concrete is important for mechanical analysis and theoretical innovation of concrete materials. In dynamic stress measurements of concrete, the matching error between the transducer and the concrete is the controlling error in the total error. To improve the measurement accuracy, in this study, the dynamic stress test method was investigated by considering the matching error. The propagation law of the time- and frequency-domain characteristics of the concrete stress under an explosion load was obtained through simulation, and the measurability of the stress was analyzed. The installation range and the minimum installation spacing of the transducers was analyzed based on the control of the matching error, and a matching error with a practical value was obtained. A stress transducer installation method was designed to meet the measurement requirements, and explosion tests were carried out. The results show that the peak value and bandwidth of the stress signal decayed rapidly with increasing propagation distance. The peak value decays exponentially, while the bandwidth decreases rapidly in the near field of the explosion to near a stable value and then rises gradually in the region close to the free boundary as the propagation distance increases. The minimum distance of the transducer from the explosives is 25 cm. The minimum distance of the transducer from the concrete boundary is 20 cm. The minimum installation distance of the transducers is 18 times the transducer thickness.