大学物理 ›› 2017, Vol. 36 ›› Issue (8): 70-75.doi: 10.16854 /j.cnki.1000-0712.2017.08.019

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基于达朗贝尔公式对一端固定一端作受迫振动的有界弦振动问题的求解

韩颖达   

  1. 山东大学物理学院,山东济南250100
  • 收稿日期:2016-12-12 修回日期:2017-02-20 出版日期:2017-08-20 发布日期:2017-08-20
  • 作者简介:韩颖达( 1997—) ,女,山东泰安人,山东大学物理学院2014 级本科生.

Study of one-dimensional finite string vibrating problem with one end fixed and the other doing forced vibration based on the D’alembert formula

HAN Ying-da   

  1. School of Physics,Shandong University,Jinan,Shandong 250100,China
  • Received:2016-12-12 Revised:2017-02-20 Online:2017-08-20 Published:2017-08-20

摘要: 通过延拓为奇函数和恰当的函数两种方式对弦的两端点进行延拓,运用达朗贝尔公式解决了一端固定,另一端作 受迫振动Asin ωt 的有界弦振动的定解问题,通过计算结果表达式直接得出了描述有界弦振动运动的物理量,直观分析出弦振 动的运动过程.同时对该问题进行了拓展,运用行波法解决了一端为齐次的第一类或第二类边界条件另一端为非齐次边界条 件的定解问题.

关键词: 达朗贝尔公式, 延拓, 有界弦振动, 受迫振动, 行波法

Abstract: Through some fit continuation,the one -dimensional finite string vibrating problem with one end fixed and the other end doing forced vibration of Asin ωt is solved by the D'alembert formula. Based on the result expressed in a concise way,some variables to describe wave propagation are obtained and the process of the string vibration is analyzed. Furthermore,the problem of fixing solution with the first or second type boundary condition on one end and inhomogeneous boundary condition on other end is solved by using traveling wave method.

Key words: D'alembert formula, continuation, vibrating string, forced vibration, traveling wave method