Mechanical Properties Of Syntactic Foams Research Articles

Vinyl Ester—Glass Hollow Particle Composites: Dynamic Mechanical Properties at High Inclusion Volume Fraction

This study entails the analysis of dynamic mechanical properties of hollow particle filled composites, called syntactic foams. A theoretical model is developed to predict the dynamic mechanical behavior of composite materials containing particle volume fraction up to the packing limit. The modeling approach is based on a differential scheme that extrapolates the properties of infinitely dilute dispersions of hollow particles (microballoons) to high inclusion volume fraction. The model is capable of predicting storage modulus and loss tangent in a wide frequency band of mechanical vibrations. Theoretical predictions are validated with experimental results on 16 compositions of vinyl ester—glass microballoon syntactic foams. Vibration methods are used to assess the dependence of dynamic mechanical properties of syntactic foams on microballoon wall thickness and volume fraction. Theoretical predictions are in close agreement with experimental findings over a wide range of vibration frequencies. Results show that loss tangent generally decreases as the inclusion volume fraction increases and is almost unaffected by microballoon wall thickness and that storage modulus increases with increasing microballoon wall thickness. Therefore, the loss tangent and the storage modulus can be tailored by means of microballoon volume fraction and wall thickness.

Compressive and fracture properties of syntactic foam filled with hollow plastic bead(HPC)

The compressive mechanical properties of syntactic foams reinforced by hollow plastic beads were studied by the quasi-static compression test. The failure mechanism of syntactic foams was also investigated by macroscopic and microscopic observation on the fractured specimens. The experimental results show that the density of syntactic foams is still the key factor affecting their mechanical properties. The macroscopic and microscopic observation on the fractured specimens indicates that the main failure mode is the elastic-plastic collapse caused by shear.

Effect of low-density filler on mechanical properties of syntactic foams of cyanate ester

Syntactic foam composites of cyanate ester with varying volume fractions of resin and glass microballoon were processed and evaluated for tensile, flexural and compressive properties. The effect of nature and volume fraction of microballoon on the mechanical properties was studied. The mechanical properties showed a gradual decrease in strength with increase in volume fraction of microballoon. The specific strength values also manifested a similar order. A similar behaviour was observed for syntactic foams with microballoons of varying true density. The properties increased proportional to the strength of the microballoon in resin-rich systems implying a strong microballoon-resin interface, corroborated by Scanning Electron Microscopy studies. The compressive modulus showed a decreasing trend with enhanced microballoon loading.

Correlation of Processing Methodology to the Physical and Mechanical Properties of Syntactic Foams With and Without Fibers

The effect of processing on the entrapment of voids in both fiber-free and fiber-bearing syntactic foam systems is studied. The process modifications for reinforced foam systems decreased the amount of voids. Foams with different void contents were later on tested for evaluating the compressive strengths. Also recorded were the strengths in two mutually perpendicular axes of the cast reinforced system. It was found that strength of syntactic foams increased as void content decreased, emphasizing that a good correlation between the two parameters exists.