Failure Mechanisms Of Sandwich Panels Research Articles

Experimental study on failure mechanisms of sandwich panels with multi-layered aluminum foam/UHMWPE laminate core under combined blast and fragments loading

This paper presents an experimental investigation into the failure mechanisms of sandwich panels with multi-layered aluminum foam/UHMWPE laminate cores under combined blast and fragments loading. The combined loading was generated by detonating a cylindrical TNT charge whose bottom face was attached with prefabricated fragments. Attention focused on the effects of UHMWPE laminate location, foam core gradation and refractory interlayer on the dynamic responses of the panels. Multiple failure patterns were observed on the panel components, including the perforations of front face, petalling or cracking of back face, plugging of foam core, scorching, fiber fracture and delamination of UHMWPE laminate, and debonding failure of adhesive. Results indicated that introducing the UHMWPE laminate was beneficial to alleviating the damage state of back face. The foam layers with graded density could further decrease the back face deflection, while the incorporation of a ceramic fiber felt would deteriorate the back face damage. As expected, the sandwich panels suffered much more destructive damage under combined loading than the ones under bare blast loading. The core configuration with the UHMWPE laminate located at the bottom layer was favored by the panels to possess a desirable capacity of comprehensive protection under combined loading and bare blast loading.

Mechanical properties and failure mechanisms of sandwich panels with ultra-lightweight three-dimensional hierarchical lattice cores

Mechanical properties and failure mechanisms of sandwich panels with “corrugated-pyramidal” hierarchical lattice cores were investigated through analytical modeling and detailed numerical simulations. This included studying the behavior of hierarchical lattice core material under compression and shearing, as well as investigating the mechanical performance of sandwich panels subjected to in-plane compression and three-point bending. Failure maps were constructed for the hierarchical lattice cores, as well as sandwich panels with hierarchical lattice cores by deriving analytical closed-form expressions for strength for all possible failure modes under each loading. 3D printed samples were manufactured and tested under out-of-plane compression in order to provide limited experimental validation of the study. Our study provides insights into the role of structural hierarchy in tuning the mechanical behavior of sandwich structures, and new opportunities for designing ultra-lightweight lattice cores with optimal performance.

Structural behaviour of composite sandwich panels with plain and fibre-reinforced foamed concrete cores and corrugated steel faces

This paper studies the four-point bending response and failure mechanisms of sandwich panels with corrugated steel faces and either plain or fibre-reinforced foamed concrete core. Mechanical properties of both plain and polyvinyl alcohol fibre-reinforced foamed concrete were obtained, which are needed for the design of sandwich panel and numerical modelling. It is found that the fibre-reinforcement largely enhances the mechanical behaviour of foamed concrete and composite sandwich panels. Finite element code Abaqus/Standard was employed to investigate the influence of face/core bonding and fastening on the four-point bending response of the sandwich panels. It was found that face/core bonding plays a crucial role in the structural performance while the influence of fastening is negligible.