钢纤维混凝土板在冲击与爆炸荷载下的K&C模型

K&C Model of Steel Fiber Reinforced Concrete Plate under Impact and Blast Load

钢纤维混凝土(Steel fiber reinforced concrete,SFRC)具有优异的延性、韧性及能量吸收能力,被广泛应用于各类防护结构。K&C模型已成为研究普通混凝土构件动力响应的常用材料模型,但仍无法准确表征SFRC的动力特性。为了提高K&C模型在冲击及爆炸荷载作用下预测SFRC板动力响应的能力,对K&C模型进行了改进:基于大量三轴压缩实验数据,建立了新的失效强度面参数模型;采用反复试验法,建立了新的损伤演化模型,并校准了拉、压损伤参数;基于大量高应变率下SFRC的单轴压缩实验数据,建立了新的受压动力增强因子模型。通过LS-DYNA显式有限元动力分析软件模拟了SFRC板的动力响应,模拟结果验证了上述改进的有效性与可靠性。

Steel fiber reinforced concrete(SFRC)is widely used in protective structures due to its excellent ductility,toughness and energy absorption capacity.K&C model is a common constitutive model for studying the response of normal concrete components under impact and blast loads,but it cannot accurately characterize the dynamic response of SFRC.In order to improve prediction of K&C model for the dynamic response of SFRC plate under impact and blast load,this work improves K&C model:a new failure strength surface parameter model was established based on a large number of triaxial compression experimental data,a new damage evolution model was established by trial-and-error method,and the damage parameters of tensile and compressive were calibrated.A new compression dynamic increase factor(CDIF)model was established based on a large number of uniaxial compression experimental data of SFRC under high strain rate.The dynamic response of SFRC plate is simulated by explicit dynamic analysis software LS-DYNA.The effectiveness and reliability of the above improvements have been verified by simulation results.