Fast modification-aimed stress modal analysis of thin plates with holes/notches

Abstract

Thin plates are widely applied in engineering structures due to their excellent mechanical performance. This paper studies the stress modal analysis (SMA) of thin plates with holes/notches for the purpose of local structural dynamic modification (SDM). Identification of predominant components of stress state at critical locations is theoretically demonstrated. To pursue possible dynamic stress reduction, a fast modification strategy is proposed by using the SMA information, which involves a two-step procedure. First, modal participation factors (MPFs) are validated in SMA and then utilized to determine the predominant modes. Second, components of stress are evaluated for the predominant stress mode shapes (sSMSs11The superscript is to distinguish the stress from the strain in present paper.). Structural dynamic simulations of a representative L-shaped thin plate with hole/notches were implemented. The sSMSs in x-, y-, and xy- directions were compared in details. Together with MPFs, sSMSs can help to identify the dangerous stresses (both the location and the direction), and then to modify the local structure to suppress dynamic stress response. By taking full advantage of numerically-obtained sSMSs along different directions, local structural modification for dynamic stress reduction can be applied in a straightforward way with high efficiency prior to the full dynamic response analysis. This research is aimed to serve as a first step towards the development of SMA-based SDM strategy for real thin-walled structures with more complex geometric details and local changes.