刘璐, 吴斌, 李伟, 欧进萍. 等效线性化方法在自复位防屈曲支撑结构中的应用[J]. 工程力学, 2016, 33(3): 204-213. DOI: 10.6052/j.issn.1000-4750.2015.01.0052
引用本文: 刘璐, 吴斌, 李伟, 欧进萍. 等效线性化方法在自复位防屈曲支撑结构中的应用[J]. 工程力学, 2016, 33(3): 204-213. DOI: 10.6052/j.issn.1000-4750.2015.01.0052
LIU Liu, WU Bin, LI Wei, OU Jin-ping. THE APPLICATION OF THE EQUIVALENT LINEARIAZATION METHODOLOGY IN SELF-CENTERING BUCKLING-RESTRAINED BRACED FRAMES[J]. Engineering Mechanics, 2016, 33(3): 204-213. DOI: 10.6052/j.issn.1000-4750.2015.01.0052
Citation: LIU Liu, WU Bin, LI Wei, OU Jin-ping. THE APPLICATION OF THE EQUIVALENT LINEARIAZATION METHODOLOGY IN SELF-CENTERING BUCKLING-RESTRAINED BRACED FRAMES[J]. Engineering Mechanics, 2016, 33(3): 204-213. DOI: 10.6052/j.issn.1000-4750.2015.01.0052

等效线性化方法在自复位防屈曲支撑结构中的应用

THE APPLICATION OF THE EQUIVALENT LINEARIAZATION METHODOLOGY IN SELF-CENTERING BUCKLING-RESTRAINED BRACED FRAMES

  • 摘要: 自复位防屈曲支撑(SCBRB)由复位系统和耗能内芯组成,由于其综合了自复位体系和防屈曲支撑的优点,经过合理设计可兼具良好的复位及耗能能力,因此更有利于实现可恢复的结构这一抗震目标。若主体结构保持弹性,则自复位防屈曲支撑框架(SCBRBF)的简化恢复力模型为双线性弹性+双线性弹塑性合成的三线性滞回模型。等效线性化方法的精度对于等效阻尼比和等效刚度的计算方式比较敏感,不同的恢复力模型以相同的等效线性化方法计算精度也不相同,因此应根据具体情况对结果进行修正,以提高计算精度和结构的安全性。首先,分别对两种等效线性化方法计算自复位防屈曲支撑结构地震位移的平均误差及变异系数展开了参数研究。结果表明:由于SCBRBF的非线性和塑性程度均低于理想弹塑性结构,因此与理想弹塑性结构相比,用两种等效线性化方法评估自复位结构地震位移反应时,尤其在周期大于0.3 s时,精度显著提高;等概率幅值平均等效线性化方法由于考虑了所有位移对等效阻尼比和等效刚度的贡献,因此比割线刚度法更为精确。其次,根据分析结果给出了不同等效线性化方法在计算SCBRBF时的修正系数。最后,根据阻尼比函数得到各个参数对阻尼比的影响规律,并给出最佳延性比。

     

    Abstract: A Self-centering Buckling-restrained Brace(SCBRB) consists of a self-centering system and energy dissipating cores. It combines the merits of both self-centering brace and Buckling-restrained Brace. Thus, it can help to realize the resilience of a structure if properly designed. Once the main frame can maintain elastic under the expected earthquakes, the restoring force model of an SCBRB frame(SCRBRF), which is the combination of the bilinear elastic and bilinear elastoplastic model, is trilinear. Since the precision of the Equivalent Linearization Methods(ELM) is dependent on the calculation method of the equivalent damping ratio and equivalent period, and is also sensitive to the hysteretic model, the result of the Equivalent Linearization Method for SCRBRF may need correction for better evaluation. Firstly, parametric study of the mean difference and the standard deviation of the difference between seismic displacement obtained by two ELMs and nonlinear Response History Analysis have been performed. Result shows that displacement calculated using the two ELMs for SCBRBFs is generally more accurate, especially for T> 3 s, when compared with elastoplastic hysteretic model. This could be attributed to decreased nonlinearity and plasticity in SCBRBFs. The ASD Method is more accurate than the R-H Method as the former considers the contribution of all displacement that the structure has experienced when calculating the equivalent period and equivalent damping ratio. Secondly, correction factor of different ELMs for the evaluation of displacement has been recommended. Finally, the effect of the key parameters on the equivalent damping ratio has been investigated according to the function of the damping ratio and the optimum ductility ratio has been presented for SCBRBF.

     

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