爆炸荷载下基于细观建模的素/钢筋混凝土板破坏模式

为了获得爆炸荷载下细观结构对素/钢筋混凝土板的影响，采用随机骨料投放建立了素/钢筋混凝土板细观模型。利用LS-DYNA对基于细观建模的钢筋混凝土板进行爆炸荷载作用下的数值模拟，通过与实验以及均质建模方法进行比较，验证了细观建模方法的准确性。进而研究了基于细观建模的素/钢筋混凝土板在不同爆炸荷载下的结构响应，获得了素/钢筋混凝土板的响应过程和破坏模式。结果表明:在低药量（1、2 kg）爆炸荷载下，细观结构对素/钢筋混凝土板的影响较小，其破坏模式以纵横塑性铰线破坏为主，药量越大，铰线越多；在高药量（5、10和15 kg）爆炸荷载下，细观结构对素/钢筋混凝土板的影响较大，与均质模型相比存在较大差异，细观素/钢筋混凝土板以爆坑为中心，产生环向与径向裂纹，药量越大，圆坑越大，裂纹越多，板局部破坏越严重。

Dynamic response of mesoscopic plain/reinforced concrete slabs under blast loading

In order to obtain the effect of meso-structure on plain/reinforced concrete slabs under explosive loading, a meso-structure model of plain/reinforced concrete slabs with stochastic aggregate method was adopted. LS-DYNA was used for numerical simulation of reinforced concrete slabs based on meso-modeling under explosive loading. The accuracy of the meso-modeling method was verified by comparing with the experimental and homogeneous modeling methods. Furthermore, the structural dynamic response of plain/reinforced concrete slabs based on meso-modeling under different explosive loads was studied, and the response process and failure mode of plain/reinforced concrete slabs were obtained. The results show that the meso-structure has little effect on the plain/reinforced concrete slab under low explosive loading (1 kg and 2 kg). The failure mode is mainly based on the vertical and horizontal plastic hinge damage. The larger the dose, the more the hinge line. Comparatively, the meso-structure has a great influence on the plain/reinforced concrete slab under the high explosive load (5 kg, 10 kg and 15 kg), and there is a big difference compared with the homogeneous model. The plain/reinforced concrete slab is centered on the blasting pit and produces circumferential and radial cracks under high explosive loading (5 kg, 10 kg and 15 kg). The larger the dose, the larger the round pit, the more cracks, the more serious the local damage.