In a significant stride for maritime engineering, researchers have developed a novel approach to analyze and mitigate vibrations in sandwich composite structures, a breakthrough that could revolutionize the design and optimization of ships and offshore platforms. The study, led by Hamidreza Rostami from the Department of Maritime Engineering at Amirkabir University of Technology in Tehran, Iran, focuses on the nonlinear vibration attenuation of sandwich beams with viscoelastic cores and graphene-reinforced face sheets.
Sandwich structures, comprising two face sheets surrounding a core material, are widely used in the maritime industry due to their high strength-to-weight ratio and excellent damping properties. However, these structures often face challenges related to vibrations, which can lead to fatigue, reduced structural integrity, and increased noise levels. Rostami’s research addresses these issues by incorporating both geometric and material nonlinearities into the analysis, providing a more accurate and comprehensive understanding of the vibrational behavior of these structures.
The study employs the Extended Higher-Order Sandwich Panel Theory (EHSAPT) to derive coupled nonlinear governing equations, which are then solved to calculate the natural frequencies and loss factors of the viscoelastically damped sandwich beam. This approach allows for the analysis of large vibration amplitudes and high damping, making it particularly relevant for maritime applications where structures are subjected to significant dynamic loads.
One of the key innovations of this research is the use of a displacement control technique that simultaneously accounts for both geometric and material nonlinearities. As Rostami explains, “This is the first time that such a technique has been enhanced to consider both types of nonlinearities, making it valid for large vibration amplitudes and high damping.” This advancement is crucial for the maritime industry, where structures often operate under extreme conditions and require robust and reliable damping solutions.
The study also investigates the effects of various parameters, such as weight fraction, graphene platelet distribution pattern, core-to-face sheet thickness ratio, boundary conditions, viscoelastic core temperature, and vibration amplitude. These insights provide valuable guidance for the design and optimization of sandwich structures in maritime applications.
The commercial impacts of this research are substantial. By improving the vibrational characteristics of sandwich structures, maritime engineers can enhance the durability, safety, and performance of ships and offshore platforms. This can lead to reduced maintenance costs, extended service life, and improved comfort and safety for crew and passengers. Additionally, the use of graphene-reinforced face sheets offers opportunities for lightweight and high-strength materials, which can contribute to fuel efficiency and reduced emissions.
Rostami’s research was published in the journal ‘Composites Part C: Open Access’, which translates to ‘Composites Part C: Open Access’ in English. This open-access format ensures that the findings are widely accessible to researchers, engineers, and industry professionals, facilitating further advancements in the field.
In summary, Rostami’s study represents a significant step forward in the analysis and mitigation of vibrations in sandwich composite structures. By incorporating both geometric and material nonlinearities, this research provides valuable insights and practical solutions for the maritime industry, paving the way for improved design, optimization, and performance of ships and offshore platforms.