| 陈学良,金星,陶夏新,李宏宇.土体动力"广义阻尼比退化系数"本构模型[J].计算力学学报,2009,26(2):245~251 |
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| 土体动力"广义阻尼比退化系数"本构模型 |
| Dynamic constitutive model for soils based on generalized damping degradation coefficient |
| 投稿时间：2007-03-20 |
| DOI：10.7511/jslx20092017 |
| 中文关键词: "广义阻尼比退化系数" 本构模型 试验阻尼 工程应用 |
| 英文关键词:generalized damping degradation coefficient constitutive model soils test damping engineering application |
| 基金项目:中国博士后科学基金一等资助(20070420047)和国家自然科学基金(50808162)联合资助项目. |
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| 中文摘要: |
| 针对土动力试验中土体反向卸载(或加载)曲线形状有时表现为先变化平缓后变化剧烈这一特征,基于原来的"阻尼比退化系数"本构模型和土体实验结果G/Gmax-γ和λ-γ曲线,给出了不规则荷载作用下曲线形状可调的"广义阻尼比退化系数"本构模型,并阐述了第二种"阻尼比退化系数"模型、"广义阻尼比退化系数"模型的函数表达式及实现过程。通过对试验阻尼比的模拟表明,所建立的加卸载准则尤其能准确拟合试验阻尼值,是对广义Masing准则的一种简化及实用化。由于调制因子Ad的可变性,它较原模型有更强地模拟试验本构曲线形状的能力。针对台湾LotungDHB钻井台阵试验场地,"阻尼比退化系数"模型和"广义阻尼比退化系数"模型分别进行了非线性地震反应分析,并将结果与强震观测记录进行比较,结果表明:"广义阻尼比退化系数"模型计算的复合加速度地震动的峰值大小、波形大小相对关系及后续波形,与实际地震记录较相一致,说明了模型的合理性以及实际工程应用的可行性。 |
| 英文摘要: |
| Firstly, based on previous Damping Degradation Coefficient Constitutive Model(DDCCM), and the basic characteristic curves G/Gmax-γ and λ-γ revealed by the results of the soil dynamic tests, the rules of adjustable generalized damping degradation coefficient constitutive curves of reverse unload after load process (or reverse load after unload process) in irregular load history are established, and function expression and implement of the second DDCCM and Generalized DDCCM (GDDCCM) are expounded for the characteristics of reverse load or unload curves sometimes change more flatly at first and then acutely. Secondly, by comparisons of 4 methods simulated results of soil test damping, the load and unload rules of GDDCCM accord with the test results, especially accord with the value of soil test damping, and they can be regarded as the simplification and practicality of Generalized Masing Rule. Because the adjustment coefficient Ad can be changed, the model has more powerful capability of simulation the shape of constitutive relationship curves. At last, using the borehole array records of Taiwan Lotung DHB field test, the nonlinear seismic response of DHB site are analyzed by DDCCM and GDDCCM respectively. After compared all the synthesize acceleration ground motions with the observation records, it is founded that PGA of GDDCCM are very close to the observation values, and the comparative size relations of waveform, subsequence waveform are agree relatively well with the records. As a result, the rationality of GDDCCM and the feasibility in practical engineering application are manifested. |
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