张衡候风地动仪的原理复原研究

Reconstruction of Mechanical Principles of the Zhang Heng's Seismoscope

候风地动仪复原研究的分歧源于工作原理不清 ,影响到外形复原的合理性和对地动仪科学地位的公正评价。针对百年来悬垂摆和直立杆这两种基本原理的猜测 ,作者从现代地震学的角度出发 ,对验震器的特点、《后汉书》的记载、都柱结构与运动、陇西历史地震、洛阳的烈度以及洛阳地震台的现代地震记录图等进行了研究。认为候风地动仪的工作原理是悬垂摆 ,触发地动仪运动的是瑞利面波 ,共振起到放大作用。长期流行的直立杆原理 (曾一度被误称为“倒立摆”)是不合理的。

The discrepancies on reconstruction of the Zhang Heng's Seismoscope resulted mainly from the ambiguities of its mechanical principles;it harms directly the reasonableness the reconstruction of its external form reconstruction,as well as and fair evaluation of the seismoscope for its academic status in scientific development.According to two kinds of basic conjectures for its mechanical principles proposed previously assumed in the last hundred years,i.e.,suspended pendulum and upright rod,authors have conducted performed comprehensive study from the viewpoint of modern seismology.The study related to different aspects of analyzing properties of seismoscope,specification in Houhan Shu (History of the Latter Han Dynasty,by Fan Ye),structure and movement of the general pillar,historical earthquakes in the history of the Longxi area,earthquake intensity at Luoyang,as well as seismograms of the Luoyang seismic station.It therefore comes to the conclusion that the mechanical principle of the Zhang Heng's seismoscope should be a suspended pendulum,the seismic Rayleigh wave plays a trigger function to the instrument and resonance make the instrument working sensitively.The principle of upright rod is of unsteady balance,mistakenly called as inverted pendulum for a time.This principle is incorrect and unreasonable though this conjecture is popular with prevalent for a long period of time.Both theoretical research and practice show that it cannot be used in seismoscope and will lead to irrational reconstruction of external form.