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基于CSC模型的UHPC低速冲击压缩性能研究

Study on low-speed impact compression performance of UHPC based on CSC model

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为探讨超高性能混凝土(ultra-high performance concrete,UHPC)材料在低速冲击压缩下的力学性能,应用大型有限元程序LS-DYNA,结合UHPC材料性能,校准了混凝土连续面盖帽(continu-ous surface cap,CSC)模型中的参数取值,建立了基于SHPB技术的UHPC低速冲击压缩数值模型并与试验验证,在此基础上探讨了低速冲击下试件单轴抗压强度和应变率对UHPC动力增大系数(dynamic increase factor,DIF)的影响,提出了 UHPC动力增大系数数值回归公式.结果表明:基于合适的参数选取,应用校准后CSC模型建立的UHPC动态冲击压缩数值仿真模型具有较好的精准性;在不同的单轴抗压强度下,应用CSC模型得到的UHPC试件前后端面应力比变化趋势大致相同,但随着应变率的提高,CSC模型模拟效果表现出相对下降的趋势;UHPC动力增大系数随着应变率的提高而增大,随着单轴抗压强度的增大而逐渐降低,表现出明显的应变率效应和强度效应;建立的耦合应变率和单轴抗压强度的UHPC动力增大系数计算公式能较好地吻合数值分析结果,并在一定程度上避免高估UHPC动力增大系数,对低速冲击作用下UHPC动力特性评估具备一定的适用性.
To discuss the behavior of ultra-high performance concrete(UHPC)under a low-speed com-pressive impact,the parameters of continuous surface cap(CSC)model in the LS-DYNA are calibrated,based on the material characteristics of UHPC.The low-speed impact analysis model of UHPC using SHPB technology is established and verified with experimental results.On this basis,the effect on the dynamic in-crease factor(DIF)varying in the uniaxial compressive strength and strain rate of UHPC specimen under the low-speed impact is discussed.A regression formula to calculate DIF for UHPC is established.The re-sults are as follows:Based on appropriate parameter values,the established analysis model using the cali-brated CSC model for UHPC has an accepted accuracy.The variation trend of the stress ratio between the front-end and rear-end of UHPC specimen under different uniaxial compressive strengths is generally simi-lar,but the simulation effect demonstrates a downtrend with the increase of strain rate for the calibrated CSC model.The DIF value of UHPC increases with the increase of strain rate,but decreases with the in-crease of uniaxial compressive strength,indicating the clear strain rate and strength effects.The formula to calculate DIF for UHPC coupling with strain rate and uniaxial compressive strength can well agree with the analysis results and avoid overestimating the DIF values of UHPC to a certain extent,indicating certain ap-plicability for estimating the dynamic behavior of UHPC under a low-speed impact.

CSC modelUHPClow-speed impactSHPBdynamic increase factor

任亮、喻贤明、万超、何瑜

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华东交通大学土建学院,330013南昌

华东交通大学土木工程国家实验教学示范中心,330013南昌

CSC模型 UHPC 低速冲击 SHPB 动力增大系数

国家自然科学基金资助项目江西省自然科学基金资助项目江西省重点研发计划一般项目

5206802420192BAB20604220202BBG73035

2024

应用力学学报
西安交通大学

应用力学学报

CSTPCD北大核心
影响因子:0.398
ISSN:1000-4939
年,卷(期):2024.41(4)
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