Published Paper Details:

A certain combination of in-plane load parameter values and the natural frequency of transverse vibration can cause unstable transverse vibrations in structural materials subjected to in-plane periodic stresses, which can result in parametric resonance. This instability may arise under compressive loads throughout a range of excitation frequencies, below the structure's critical load. Many strategies for preventing parametric resonance, such vibration isolation and dampening, may not be sufficient or safe at times, leading to unfavorable outcomes. Unlike the primary resonance, the parametric instability can occur even for modest excitation amplitudes and combinations of frequencies, not just at a single excitation frequency. When a structure is subjected to in-plane periodic stress, it is possible to discriminate between good and undesirable vibration regimes by analyzing its dynamic instability region (DIR) spectrum. These spectra are frequently calculated and given in terms of natural frequencies. Therefore, a crucial component of the dynamic instability study of composite plates and shells in a hygrothermal environment is the very precise estimation of these values.