Model experimental study on strain field evolution and damage distribution of filling body under blast loading. (10th April 2023)

• Record Type: Journal Article
• Authors: Zhao, Yong; Yang, Renshu; Fang, Shizheng; Wang, Yu; Wang, Wenliang
• Is Part Of: Construction & building materials. Volume 373(2023)
• Publication Date: 2023-04-10
• Subjects: Blast loading -- Strain field -- Damage distribution -- Filling body -- Digital image correlation; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2023.130798
• Languages: English
• ISSNs: 0950-0618

Abstract

Abstract: Ensuring the stability of filling bodies is an important part of safe construction in the mining process of the filling body method in metal mines. As blast loading is one of the main external factors affecting the stability of filling bodies, it is of great significance to study the failure mechanism of filling bodies under blast loading for guiding the actual production. In this study, a self-made mould was used to develop a plane explosive loading model of an ore-filling body. Based on this model a Digital Image Correlation (DIC) technology-hyperdynamic strain synchronization test system was established, and the strain data collected by the two systems were compared. The results showed that the variation trend and peak strains of the two systems over time were consistent. Further, based on the DIC method and fractal theory, the ore diameter and explosive equivalent were selected as dependent variables to vary the blast loading strength, and the damage distribution characteristics and strain field evolution law of the filling body under different blast loading strengths were studied. The results showed that the filling body exhibited a single failure pattern of radial crack under low blast loading and a composite failure pattern of radial and circumferential crack under high blast loading. With the increase in the intensity of load, the radial crack number increased gradually. When the explosive equivalent was taken as a single variable, the damage degree of the filling body varied linearly with the explosive amount. Under the action of blast loading, the von Mises strain field in the filling body decayed exponentially along the radial direction from the explosion source. The change in blast loading intensity had a significant impact on the strain field close to the ore-filling interface but had less of an impact on the strain field farther away from the ore-filling interface. Specifically, when the initial load intensity of the filling body was high, the strain field near the interface of the filling body showed the characteristics of "high intensity and fast attenuation", while the strain field intensity was low in the distant area. When the initial load intensity was low, the intensity of the full-field strain field in the filling body was low, exhibiting the change characteristics of "slow decay".