Ultraviolet-Activated Frequency Control of Beams and Plates Based on Isogeometric Analysis

A new light-activated shape memory polymer (LaSMP) smart material exhibits shape memory behaviors and stiffness variation via ultraviolet (UV) light exposures. This dynamic stiffness provides a new noncontact actuation mechanism for engineering structures. Isogeometric analysis (IGA) utilizes high order and high continuity nonuniform rational B-spline (NURBS) as basis functions which naturally fulfills C¹-continuity requirement of Euler–Bernoulli beam and Kirchhoff plate theories. Compared with the traditional finite elements of beams and plates, IGA does not need extra rotational degrees-of-freedom while providing accurate results. The UV light-activated frequency control of LaSMP fully and partially laminated beam and plate structures based on the IGA is presented in this study. For the analysis of LaSMP partially laminated plates, the finite cell approach in the framework of IGA is proposed to handle NURBS geometries containing trimming features. The accuracy and efficiency of the proposed isogeometric approach are demonstrated via several numerical examples in frequency control. The results show that, with LaSMPs, broadband frequency control of beam and plate structures can be realized. Furthermore, changing LaSMP patch sizes on beams and plates further broadens its frequency control ranges. Studies suggest that: (1) the newly developed IGA combining finite cell approach is an effective numerical tool and (2) the maximum frequency manipulation ratios of beam and plate structures, respectively, reach 24.30% and 16.75%, which demonstrates the feasibility of LaSMPs-induced vibration control of structures.