司理涛, 赵岩, 张亚辉. 移动随机线源荷载作用下黏弹性半空间体的动力响应[J]. 工程力学, 2016, 33(6): 98-106. DOI: 10.6052/j.issn.1000-4750.2014.06.0497
引用本文: 司理涛, 赵岩, 张亚辉. 移动随机线源荷载作用下黏弹性半空间体的动力响应[J]. 工程力学, 2016, 33(6): 98-106. DOI: 10.6052/j.issn.1000-4750.2014.06.0497
SI Li-tao, ZHAO Yan, ZHANG Ya-hui. DYNAMIC RESPONSE OF VISCOELASTIC HALF-SPACE SUBJECTED TO MOVING RANDOM LINE LOADS[J]. Engineering Mechanics, 2016, 33(6): 98-106. DOI: 10.6052/j.issn.1000-4750.2014.06.0497
Citation: SI Li-tao, ZHAO Yan, ZHANG Ya-hui. DYNAMIC RESPONSE OF VISCOELASTIC HALF-SPACE SUBJECTED TO MOVING RANDOM LINE LOADS[J]. Engineering Mechanics, 2016, 33(6): 98-106. DOI: 10.6052/j.issn.1000-4750.2014.06.0497

移动随机线源荷载作用下黏弹性半空间体的动力响应

DYNAMIC RESPONSE OF VISCOELASTIC HALF-SPACE SUBJECTED TO MOVING RANDOM LINE LOADS

  • 摘要: 求解移动荷载作用下黏弹性半空间体的响应,是研究交通荷载引起的环境振动问题的基础。移动荷载作用下半空间体响应的积分形式解不难得出,但当荷载移动速度接近或大于瑞利波速时,被积函数往往具有奇异性和高振荡性,这就使得数值计算相当困难。该文研究了移动随机线源荷载作用下黏弹性半空间体的响应问题。利用虚拟激励法,将系统的随机振动分析转化为确定性分析,然后通过广义Duhamel积分得到了响应的积分形式解。将被积函数图形化确定了函数的积分限,通过自适应数值积分算法解决了被积函数的振荡性,最终得出了黏弹性半空间体动力响应的数值结果。为确保数值计算结果的正确性,同样计算了确定性荷载作用下半空间体的响应,并与已有文献结果进行了对比。在验证了数值算法正确性的基础上,计算了随机荷载作用下半空间体的响应,荷载移动速度涵盖了亚音速、跨音速和超音速三种情形。通过具体算例,分析了响应的时间和空间分布规律,并对荷载移动速度对响应的影响进行了分析。

     

    Abstract: It is a kind of fundamental work to obtain the dynamic response of a viscoelastic half-space subjected to moving loads for solving the environment vibration problems caused by traffic loads. Although the dynamic response of a viscoelastic half-space under moving loads in an integral form is not hard, the evaluation of these integrals is a formidable task due to the high oscillation and singularity when the loads' speed approaches or exceeds Rayleigh-wave speed. In this paper, the response of a viscoelastic half-space under moving random line loads has been studied, including uniform loads and non-uniform loads. Using the pseudo-excitation method, the stochastic analysis of the system is transformed into deterministic analysis; and then by applying Fourier transformation, the response in an integral form is developed. First, the integration interval is confirmed by visualizing the integrand; and then the oscillation of the integrand can be overcome by adopting adaptive numerically integration algorithm; finally, the numerical results are obtained. For the purpose of verification, the response of a viscoelastic half-space subjected to moving deterministic loads is also evaluated, and the numerical results have a good agreement with those in literatures. Based on the numerical method, the response of a viscoelastic half-space under moving random loads have been calculated, including the subsonic, transonic and supersonic cases. The response's distribution in time and in space as well as the contribution of different moving loads' speeds to the response are analyzed.

     

/

返回文章
返回