结构动态

Structural dynamics is about the characterisation of structural properties and the behaviour of structures when subjected to various physical forces.Whether it's awind turbine blade vibrating in an offshore gale，an aircraft experiencing turbulence，or machinery facing self-generated vibrating，forcentheforcesture。

While structures need to be resilient and rigid，over-engineering can be both unnecessary and costly，especially when weight is a concern.And some structures，such as engine mounts，must not be overly rigid asthey need to absorb vibration to enhance comfort。

Structural dynamics is about the characterization of structural properties and the behaviour of structural properties are expressed in a set of modal parameters，each consisting of mode shape with an associated natural（resonance）frequency and damping value。“modal parameters are derived from a mathematical model describing the relationship between the inputs and outputs and can be obtained using”classical modal analysis或，或operational modal analysis（OMA）。

In the classical modal analysis，the structure is excited using impact hammers或modal exciters（modal shakers），whereas，in operational modal analysis，natural excitation is used.In both cases，the response is typically measured using accelerometers。

Determining how shocks affect a structure is a special type of structural characterization.For this purpose，theshock response spectrum（SRS）calculated from transients in the time domain is used。

Structural behavior is observed using techniques such asoperating deflection shapes（ODS）analysis for determining the vibration patterns of structures under various operating conditions or using permanent强制加热装置（SHM）to follow the structural state continuously and determine the required health management of the structure。