Review of recent research and developments on floating breakwaters

Lattice structures, which are also known as architected cellular structures, have been applied in various industrial sectors, owing to their fascinated performances, such as low elastic modulus, high stiffness-to-weight ratio, low thermal expansion coefficient, and large specific surface area. The lattice structures fabricated by conventional manufacturing technologies always involve complicated process control, additional assembly steps, or other uncontrollable factors. Furthermore, limited types of unit cells can be used to construct lattice structures when using conventional processes. Fortunately, additive manufacturing technology, based on a layer-by-layer process from computer-aided design models, demonstrates the unique capability and flexibility and provides an ideal platform in manufacturing complex components like lattice structures, resulting in an effective reduction in the processing time to actual application and minimum of material waste. Therefore, additive manufacturing relieves the constraint of structure design and provides accurate fabrication for lattice structures with good quality. This work systematically presents an overview of conventional manufacturing methods and novel additive manufacturing technologies for metallic lattice structures. Afterward, the design, optimization, a variety of properties, and applications of metallic lattice structures produced by additive manufacturing are elaborated. By summarizing state-of-the-art progress of the additively manufactured metallic lattice structures, limitations and future perspectives are also discussed.

Additive manufacturing of metallic lattice structures: Unconstrained design, accurate fabrication, fascinated performances, and challenges

This paper systematically investigates the low-velocity impact response and resulting damage behavior of aluminum honeycomb sandwich structures with carbon fiber reinforced plastic (CFRP) face sheets by combining the experimental and numerical methods. Low-velocity impact tests are conducted to determine and quantify the effects of structural parameters, such as face sheet thickness, cell wall thickness, honeycomb core height and hexagon side length, on the impact load, energy absorption, and failure mode. To further elucidate the impact behavior, a user VUMAT subroutine is developed to predict the progressive failure behavior of composite face sheets. Numerical simulation is performed to characterize the impact response and explore the deformation/failure mechanisms. The predicted impact load, energy absorption, contact time and failure mode agree well with measured counterparts. These studies reveal the face sheet thickness has particularly significant influence on the impact resistance performance of honeycomb structures. Cell wall thickness and side length of honeycomb core have notable effect on the impact load and structural stiffness of such structures, while which do not play a great role in energy absorption. Increase in core height has comparatively little effect on initial stiffness and energy absorption but makes the second peak loads decreasing for the perforation cases.

Effect of structural parameters on low-velocity impact behavior of aluminum honeycomb sandwich structures with CFRP face sheets

A review of the analysis of sandwich FGM structures

Hydrodynamic performance of a pile-supported OWC breakwater: An analytical study

Experimental study of a new type of floating breakwater

The main purpose of this paper is to provide a semi analytical method to analyze the free vibration of spherical-cylindrical-spherical shell subject to arbitrary boundary conditions. The formulations are established based on energy method and Flugge thin shell theory. The displacement functions are expressed by unified Jacobi polynomials and Fourier series . The arbitrary boundary conditions are simulated by penalty method about spring stiffness . The final solutions of spherical-cylindrical-spherical shell are obtained by Rayleigh–Ritz method. To sufficient illustrate the effectiveness of proposed method, some numerical example about spring stiffness, Jacobi parameters etc. are carried out. In addition, to verify the accuracy of this method, the results are compared with those obtained by FEM, experiment and published literature. The results show that the proposed method has ability to solve the free vibration behaviors of spherical-cylindrical-spherical shell.

Jie Cui

Papers

Experimental study of a new type of floating breakwater

Application of flügge thin shell theory to the solution of free vibration behaviors for spherical-cylindrical-spherical shell: A unified formulation

Experimental study on configuration optimization of floating breakwaters

3D experimental study on a cylindrical floating breakwater system

Hydrodynamic performance of floating breakwaters in long wave regime: An experimental study