Structural dynamics is the study of the response of structures to dynamic loads. These loads can be caused by external forces, such as wind or earthquake, or by internal forces, such as machinery vibration. The goal of structural dynamics is to predict the behavior of structures under these loads so that they can be designed to withstand them.
In order to do this, engineers first need to understand how structures respond to static loads. This understanding forms the basis for predicting how a structure will respond to a dynamic load. Static loads are applied slowly and evenly over time, so they cause deformations that are proportional to their magnitude. In contrast, dynamic loads are applied suddenly and can vary widely in magnitude and direction over time. As a result, they can cause much larger deformations than static loads of the same magnitude.
Dynamicloads also cause stresses that are not only greater in magnitude than those caused by staticloads but also have different distributions within the structure. When designing a structureto withstand dynamicloads, engineers must account for both the increased magnitudeand the different distributionof stresses.
There are two main types of structural dynamics: linear and nonlinear. Linear structural dynamics deals with small deformations and stresses that change linearly with time; it can be analyzed using classical methods such as Newton’s laws of motion. Nonlinear structural dynamics deals with large deformations and stresses that change nonlinearly with time; it requires more sophisticated methods such as finite element analysis (FEA).
Both linear and nonlinear structural dynamics are important in engineering practice; each has its own advantages and disadvantages depending on the particular problem at hand. In general, linear methods are simpler and faster than nonlinear methods but become less accurate as deformations increase; nonlinear methods are more complex but provide more accurate results for large deformations.
– Classical Methods:
– Newton’s Laws Of Motion: F=ma
– Lagrangian Mechanics: Energy Methods
– Euler-Bernoulli Beam Theory: Deflection Of Beams
– Timoshenko Beam Theory
– Plate Theory
– Shell Theory