Dynamic Buckling Of An Impacted Composite Column Subjected To Hygro-thermal Environment

Functioning as a vital engineering component, composite columns find their great popularity in fields such as aeronautics and aviation industries, architectures, bridges,and so on. Among all the influence factors is the predominant impacting load caused by other structures and sudden heavy masses. More than often, those structures work in an environment in which humidity and heat play a non-neglectable role in affecting their performances. Consequently, studying the combining effects of impacting loads and humidity and heat on the dynamic properties of structures equip this question with not only the value of academic researches, but engineering significance. Specifically,this paper will center on the united effects of impacting loads and humidity and heat on the dynamic buckling properties.Chapter one lays out the research background and the values of investigating this question. Following that, this chapter summarizes the status quo of studies of impacted metal and composite columns; attention is focused on the researches of impacted composite columns subjected to humidity and heat.In the coming after section—chapter two and three, axial and lateral vibration equations are constructed, based on the constitutive equation of a single layer of composite materials, the classic composite plate theory, and the Euler-Bernoulli beam theory. Employing the Laplace transform, the author arrives at the analytical solution to the axial movement. Substituting that analytical solution into the lateral vibration equation, the characteristic equation for frequencies is constructed, a process of discretization of the lateral vibration equation by the Galerkin method. At the end of this section, numerical calculations are presented to study the effects of factors such as impact mass, velocity; length, diameter; ply angle on the dynamic buckling time and the contact duration between the impact mass and the column.Introduced influences of humidity and heat, axial and lateral vibration equations are also constructed, based on the constitutive equation of a single layer of composite materials, the classic composite plate theory, and the Euler-Bernoulli beam theory in chapter four and five. As procedures implemented in chapter two and three, the author reaches the analytical solution to the axial movement for the column in humidity and heat environment, and the characteristic equation for frequencies is structured for the lateral vibration. Parameters, such as temperature, humidity; impact mass, velocity;length, diameter; ply angle; combination of humidity, heat, and velocity, are investigated to study their influences on the dynamic buckling and contact duration.