地震工程学报
地震工程學報
지진공정학보
China Earthquake Engineering Journal
2014年
3期
476-481
,共6页
杨宇%李小军%贺秋梅%王璐
楊宇%李小軍%賀鞦梅%王璐
양우%리소군%하추매%왕로
散射%多次透射边界%高频震荡失稳%滤波%高频能耗性
散射%多次透射邊界%高頻震盪失穩%濾波%高頻能耗性
산사%다차투사변계%고빈진탕실은%려파%고빈능모성
scattering%multi-transmitting boundary%high-frequency instability%filtering%high-frequency energy consumption
多次透射边界是一种应用广泛的人工边界,类似于其它局部人工边界,它也存在计算稳定性问题。本文分析多次透射边界高频振荡失稳的原因,通过数值试验对已有的消除高频失稳措施进行比较分析,并给出在散射问题中已有消除高频失稳措施的适用性。研究表明,对于完全弹性问题,建议用滤波方法消除高频振荡失稳,但滤波系数的取值需要依据一定的经验;对于黏弹性问题,建议适当控制阻尼取值,利用差分格式本身的高能耗特性来抑制高频振荡失稳,该方法不存在参数选取的问题,更便于应用实施。
多次透射邊界是一種應用廣汎的人工邊界,類似于其它跼部人工邊界,它也存在計算穩定性問題。本文分析多次透射邊界高頻振盪失穩的原因,通過數值試驗對已有的消除高頻失穩措施進行比較分析,併給齣在散射問題中已有消除高頻失穩措施的適用性。研究錶明,對于完全彈性問題,建議用濾波方法消除高頻振盪失穩,但濾波繫數的取值需要依據一定的經驗;對于黏彈性問題,建議適噹控製阻尼取值,利用差分格式本身的高能耗特性來抑製高頻振盪失穩,該方法不存在參數選取的問題,更便于應用實施。
다차투사변계시일충응용엄범적인공변계,유사우기타국부인공변계,타야존재계산은정성문제。본문분석다차투사변계고빈진탕실은적원인,통과수치시험대이유적소제고빈실은조시진행비교분석,병급출재산사문제중이유소제고빈실은조시적괄용성。연구표명,대우완전탄성문제,건의용려파방법소제고빈진탕실은,단려파계수적취치수요의거일정적경험;대우점탄성문제,건의괄당공제조니취치,이용차분격식본신적고능모특성래억제고빈진탕실은,해방법불존재삼수선취적문제,경편우응용실시。
The multi-transmitting boundary is a local artificial boundary widely used in the numer-ical simulation of near-field wave motions in infinite media.But,like other artificial boundaries, the multi-transmitting boundary is unstable in numerical simulations.In this paper,we analyze the cause of this high-frequency instability and discuss the applicability of previous stability measures by performing numerical scattering problem experiments.We found that(1)for the perfect elastic-ity problem,the filtering method is more suitable for eliminating high-frequency instability,but it must be used carefully because of the need to consider the empirical value of the parameters;and (2)for the viscoelastic problem,the explicit difference scheme with a suitable damping value is more suitable for eliminating high-frequency instability due to the energy dissipation of the differ-ence scheme.This scheme is also more convenient for application because no empirical parameters must be considered.