Modal analysis of pre and post impacted nano composite laminates

Abstract

Modal analysis is carried out on pre and post impacted nano composite laminates. The laminates are prepared using 3, 5 and 8 layers of 610gsm glass woven roving mats(WRM) with epoxy resin and montmorillonite(MMT) clay content is varied from 1% to 5%. Impulse hammer technique is used to find natural frequency and damping factor of laminates. Medium velocity impact tests are conducted by using a gas gun. The vibration responses of natural frequency and damping factor are obtained and are studied for laminates with all edges clamped boundary conditions. Results show considerable improvement in natural frequency and damping factor due to nano clay addition. It is also seen that the nano clay controls the delamination due to impact loading.

Vibration and Energy Dissipation of Nanocomposite Laminates for Below Ballistic Impact Loading

“…The maximum energy is dissipated in this frequency. From our previous study on modal analysis, Velmurugan and Balaganesan (2011), it is observed that this range of frequency is its fifth mode of vibration. Also it is observed that 2 mm thickness laminates vibrate in various modes up to 2000 Hz and dissipate the energy received from the projectile.…”

“…Sharp reflection peak is noticed for epoxy with 5% clay at 2.85° and corresponding interlayer distance is 46 Å which indicates that intercalated structure has been formed. The formation of intercalated structure for 5% clay content is due to non-homogenious mixing of clay and uneven curing in the intergallery and extra gallery matrix regions of the nano-XRD pattern of clay, epoxy with and without clay, Velmurugan and Balaganesan (2011).…”

Constitutive modeling of AZ31 sheet alloy with application to axial crushing

“…For safety assessment, the response of thin walled structures in compression is of particular interest. It is well documented in the literature that such loading induces bulging associated with circumferential expansion in steels (see for example, Velmurugan and Muralikannan [29] for studies on steel tubes crushing under statically or dynamical loading) or aluminum tubes (e.g. Langseth et al [30]).…”

Electrospun nanofiber interleaving in fiber reinforced composites—Recent trends

“…Traditionally, the properties and composition of the constituents play deterministic role in the eventual nature and limiting performance of the conventional composite; however, the advent of nanoengineering has ushered in a growing interest in research on nanometre scaled fillers, commonly nanofibers, which can not only enhance and tailor the properties of the composite but imbue novel functionalities. Some researchers used nanofillers interleaving to study the performance of modified composites . There exist many different methods to fabricate nanofibers, including drawing, electrospinning, self‐assembly, template synthesis, and thermal‐induced phase separation .…”