Experimental and analytical study on blast resistance performance of brick infill walls strengthened with polyuria
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摘要: 为了掌握聚脲喷涂加固砖填充墙的抗爆特性,基于一种改进的大型爆炸试验装置,开展了聚脲加固框架砖填充墙的原型爆炸试验,分析了爆炸荷载作用下加固砖墙的动力响应特征和破坏过程及模式,揭示了其失效破坏机理。研究结果表明,聚脲加固可大幅提升填充墙构件的抗爆性能,显著增加填充墙构件的变形延性;加固砖墙受爆炸荷载作用发生振动的过程其体系刚度不断变化,最高相差133%;随着比例距离降低,加固砖墙的破坏模式逐渐由弯曲破坏转为剪切破坏,聚脲厚度超过6 mm可以有效限制局部剪切破坏现象;基于砖墙和聚脲涂层的抗力函数建立的理论计算模型,可以较为准确地预测爆炸作用下背爆面加固双向砖墙的正向位移响应过程。Abstract: In order to study the blast-resistance characteristics of polyurea sprayed reinforced brick infill walls, a prototype explosion test of polyurea sprayed reinforced frame infill walls was carried out based on an improved large-scale explosion test device. This test device eliminates the influence of the sparse wave formed by the air shock wave at the edge of the wall and the diffraction behind the wall on the real blast resistance test dynamic response of the wall, and significantly improves the accuracy of the blast resistance test of brick infill walls strengthened with polyuria. The dynamic response characteristics, failure process and mode of reinforced brick walls under explosion load were analyzed, and the failure mechanism was revealed. The results show that under small deformation conditions, polyurea reinforcement can improve the blast-resistance of infilled wall members. Under large deformation conditions, polyurea reinforcement can increase the ductility of filled wall members. The system stiffness of reinforced brick wall changes continuously during forced vibration, and the maximum difference is 133%. With the decrease of the proportional distance, the failure mode of the reinforced brick wall gradually changes from bending failure to shear failure. The polyurea thickness of more than 6 mm can effectively limit the local shear failure phenomenon. The theoretical calculation model based on the resistance function of brick wall and polyurea coating can accurately predict the forward displacement response process of two-way brick wall reinforced by back blasting surface under explosion.
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Key words:
- polyuria /
- brick wall /
- blast-resistance test /
- system stiffness /
- resistance function
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表 1 砖和砂浆的力学参数
Table 1. Material parameters of brick and mortar
材料 密度/(kg·m−3) 杨氏模量/MPa 泊松比 抗拉强度/MPa 剪切强度/MPa 屈服强度/MPa 砖 1200 897 0.15 5.5 5.5 14.1 砂浆 2100 913 0.25 3.5 3.5 7.03 表 2 聚脲的力学参数
Table 2. Polyurea material parameters
密度/(kg·m−3) 杨氏模量/MPa 泊松比 抗拉强度/MPa 屈服强度/MPa 切线模量/MPa 真实失效应变 1150 80 0.17 15 5.5 14.1 1.2 表 3 试验工况
Table 3. Test conditions
试验 聚脲厚度/mm 比例爆距/(m·kg−1/3) 装药当量/kg 1 0 1.89 4 2 0 1.39 10 3 6 1.89 4 4 6 1.39 10 表 4 爆炸荷载验证
Table 4. Explosion load verification
装药/kg 冲量/(Pa·s) 误差/% 测点P1 文献[17]方法 4 306 400 23.5 10 824 790 4.3 破坏等级 边界条件 支座转角/(°) 跨中允许挠度/mm 可修复 单向 0.5 8.72 双向 0.5 8.72 不可修复 单向 1 17.45 双向 2 34.90 -
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