Study on the Damage Characteristics of RC Beams under Explosion Impact Load
S.-Z. Wu1, Z.-R. Gao1, Y.-K. Yang2, F.-Y. Zhang1, J.-X. Wu1, J.-Y. Huang1, Y.-C. Li1
1College of Field Engineering, Army Engineering University of PLA, Nanjing, China
2Key Laboratory of Chemistry for NBC Hazards Protection, Beijing, China
Keywords: damage characteristics, reinforced concrete beam, explosive impact load, dynamic response, model testing, numerical simulation
Abstract
The character, criteria, effects and other characteristics of damage to reinforced concrete beams under the action of explosive impact loading were studied experimentally and using numerical modeling methods. A fast method for obtaining the P-I curve of beam elements with arbitrary structural parameters is proposed. First, five model tests were conducted to study the dynamic response and damage parameters of two types of reinforced concrete beams with cross-sectional widths of 0.04 and 0.047 m under a 200 g TNT explosion at pre-detonation distances of 0.2 and 0.5 m and at blast locations above 1/2 and 1/4 of the span. The results showed that damage to the reinforced concrete beam was less with a cross-sectional width of 0.04 m and at a blast location above 1/2 of the span under the experimental conditions. The experimental results confirmed the effectiveness of the numerical modeling method. Based on a large number of numerical simulation results, the approximation formula for the P-I curve of reinforced concrete beams was simplified, and the influence of the following parameters on the P-I curve was investigated: stirrup reinforcement ratio ρs, longitudinal reinforcement ratio ρ, concrete axial compressive strength ƒ′c, beam span L, beam cross-section height b, and beam cross-section width a. As a result, a method for quickly determining the P-I curve of reinforced concrete beam elements is proposed, which can be applied in the field of blast protection design and rapid damage assessment.
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