Vibration-based damage identification for ship sandwich plate using finite element method

Abstract

The sandwich plate can be used to replace the conventional steel stiffened plates on the ship’s hull structure. By using the sandwich plate, not only the stiffness of the plate can be increased but also the overall ship weight can be reduced, as well as the ship payload can be increased. The sandwich plate should be accompanied by the damage identification system to prevent ship structural failure. In this paper, the global damage identification method, which is based on the vibration analysis, is investigated. For that purpose, the vibration-based damage identification using the Finite Element Method (FEM) is explored. The variables being investigated are the damage sizes, damage locations, and the boundary conditions which affect the natural frequencies of the structures. The sandwich plate considered in this study consisted of steel faceplates with the polyurethane elastomer core, which has been checked to meet Lloyd’s register, an international maritime standard. From the analysis, it is found that the fully clamped boundary conditions accompanied by high vibration modes are more sensitive to the presence of artificial damage. The changes in the natural frequencies can be used as a reference to identify the size and location of damage in the sandwich plate.

Influence of application of sandwich panel on static and dynamic behaviour of ferry ro-ro ramp door

“…Other result investigations were also mentioned by [28]. It is well-known that a fully clamped boundary condition in all sides produces higher stiffness compared to others with the same geometry parameters, as also mentioned in [19]. Moreover, the CFCF and SFSF boundary conditions have a similar frequency shift.…”

“…In the lower mode, the natural frequency is altered by small damage but not as significant as in higher modes. Several researchers also mention that debonding detection in the sandwich structure in small damage is more sensitive in higher modes [8,9,16,19]. Debonding decreases the shear stress transfer area between the faceplate and core, which can reduce the stiffness of the model.…”

“…The result can be proposed as an initial study to strengthen the efficiency of SHM. This basic principle is to compare the modal parameters between healthy and debonded models using dynamic properties such as natural frequencies [9,[15][16][17][18][19], mode shapes [20], frequency response functions (FRF) [21,22], and time or frequency domain data [8,23]. Influence of debonding size, location, and type on the modal parameter was investigated in [15].…”

Pengaruh Multiple Damages Struktur Kapal Berbahan Sandwich Panel Menggunakan Respon Getaran

“…Analisis pengaruh rasio kerusakan terhadap deviasi frekuensi natural menunjukkan bahwa semakin besar ukuran kerusakan, semakin tinggi penyimpangan frekuensi alaminya. Jika terdapat deviasi frekuensi alami tertentu pada kapal maka ukuran kerusakan dapat diprediksi [7].…”

Study of sandwich panel application on side hull of crude oil tanker

“…Combining these two material characteristics creates a sandwich effect that provides a very efficient ratio of stiffness-to-weight [3,4,5], which is an important characteristic for light structures in the ship's construction [6]. In terms of the development of SPS for ship structure, several core materials have been analyzed, such as the combination of unsaturated polyester resin (UPR) with talc powder [7], bio-resin using vinyl ester and vegetable oil [8,9], UPR with a clamshell powder [10], UPR with an eggshell powder [11], epoxy resin [6], and polyurethane elastomer (PU) [12,13,14]. Steel faceplates and room temperature cured polyurethane elastomer core are commercial materials of SPS for ship structure [2,15].…”