Undesirable cabin noise has an adverse physiological effect on passengers and crews in an aircraft. In order to reduce the noise level, a passive approach using a truss-core sandwich (TCS) panel as a sound insulator is proposed. Design guidelines and analysis methodologies were developed in order to explore the vibro-acoustic characteristics of TCS structure. Its sound isolation properties can be thereby assessed. Theoretical analyses show that the transmission-loss and sound radiation properties of a TCS structure can be represented by the root-mean-square velocity of its surface, and a beam structure analysis is sufficient to reveal many of the important aspects of TCS panel design. Using finite element analysis, a sensitivity study was performed to create design guidelines for TCS structures. Transmission-loss experiments show that the analytical and numerical analyses correctly predict the trend of TCS structure’s vibro-acoustic performance.

Undesirable cabin noise has an adverse physiological effect on passengers and crews in an aircraft. In order to reduce the noise level, a passive approach using a truss-core sandwich (TCS) panel as a sound insulator is proposed. Design guidelines and analysis methodologies were developed in order to explore the vibro-acoustic characteristics of TCS structure. Its sound isolation properties can be thereby assessed. Theoretical analyses show that the transmission-loss and sound radiation properties of a TCS structure can be represented by the root-mean-square velocity of its surface, and a beam structure analysis is sufficient to reveal many of the important aspects of TCS panel design. Using finite element analysis, a sensitivity study was performed to create design guidelines for TCS structures. Transmission-loss experiments show that the analytical and numerical analyses correctly predict the trend of TCS structure’s vibro-acoustic performance.

Among the light bending structures currently available, truss core panels are one of the most efficient when properly designed. The proper selection of the truss core lattice allows the incorporation of additional functionality. To exploit the multi-functional advantages of truss core sandwich structures, it is crucial to understand how the materials survive in challenging environments. In this research, the strengths of truss core panels have been predicted. Numerical calculations and experiments were carried out to validate the predictions. The effects of damage and damage propagation on the overall strength of the panel were also addressed. The strength and failure surfaces of arrays of partially damaged truss core unit cells were calculated under shear and axial loading. The results highlight the modes and trends of damage propagation in truss core panel, and the estimated damaged strength. Experiments were also performed to validate the damaged strength.

Among the light bending structures currently available, truss core panels are one of the most efficient when properly designed. The proper selection of the truss core lattice allows the incorporation of additional functionality. To exploit the multi-functional advantages of truss core sandwich structures, it is crucial to understand how the materials survive in challenging environments. In this research, the strengths of truss core panels have been predicted. Numerical calculations and experiments were carried out to validate the predictions. The effects of damage and damage propagation on the overall strength of the panel were also addressed. The strength and failure surfaces of arrays of partially damaged truss core unit cells were calculated under shear and axial loading. The results highlight the modes and trends of damage propagation in truss core panel, and the estimated damaged strength. Experiments were also performed to validate the damaged strength.

Low-density cellular solids have demonstrated superior mechanical properties as well as multifunctional characteristics, which may provide a basis for the development of novel structured materials. In particular, cellular solids offer great design flexibility, owing to their topology, which can provide desired functionalities via targeted geometric design and proper selection of the constituent material. While stochastic configurations such as metallic foams have proven to be effective for both thermal insulation and mechanical-energy absorption, the topology of deterministic architectures is not constrained by physical processes. This allows for a variety of configurations to be tailored to simultaneously fulfill disparate tasks. An additional aspect of deterministic cellular structures is the possibility of assembling materials or structures by the spatial repetition of a unit cell. The resulting periodicity of such systems simplifies the characterization of physical properties, which can be established by analyzing the unit cell only, and will provide new opportunities in the fields of structural dynamics, where periodicity-induced impedance leads to the control of both constructive and destructive interference on propagating waves. The objective of this work is to investigate the application of the chiral cellular topology for the design of novel macrostructural, mesostructural and microstructural configurations. A truss-core airfoil, and a truss-core beam are employed as a basis to demonstrate both large-displacement capabilities within the elastic regime of the constituent material, as well as operational deflection shapes with localized dynamic deformations. Large deformation capabilities and unique operational deflection shapes are to be attributed to the unusual deformation mechanism of the chiral lattice. Mesostructural and microstructural configurations, on the other hand, are characterized by an unique mechanical behavior, complex geometry, as well as geometric design flexibility to control both static and dynamic phenomena. The propagation of elastic waves, moreover, is characterized by significant band-gap density as well as strong energy focusing dependent on frequency and wavenumber. These features suggest the chiral topology as a basis for the development of acoustic meta-materials.