An experimental study on ballistic impact response of jute reinforced polyethylene glycol and nano silica based shear thickening fluid composite

The present study aims at assessing the ballistic impact behaviour of jute reinforced polyethylene glycol(PEG)and nano silica based shear thickening fluid(STF).Preparation of STF is achieved by dispersing the nano silica particles at different weight percentage loadings of 10%,20%,30%and 40%in PEG and the effect of various weight percentages loading of nano silica particles on ballistic performance of the proposed composites is studied experimentally.Rheological studies of the prepared STF’s showed that at all nanosilica loading shear thickening occurred and also the shear thickening was highest at higher loading of nano silica at lower rate of shear.The study reveals that the ballistic performance of the jute fabric is enhanced with impregnation of STF.The ballistic results indicate that energy absorption of the proposed composites is enhanced with increased loading of nano silica particles and at the same time,the effect of STF was reduced.Specific energy absorption(SEA)of the neat fabric and the proposed composites was made use of for the purpose of comparing the energy absorption capabilities.It is found that the SEA of proposed composites with 10%nano silica loading is lesser than the neat fabric both in case of 3 layers and 6 layers.It was also found that proposed composite with 40%nano silica loading exhibits highest SEA compared to neat fabric and its counterparts with its SEA being 3.21 and 3.76 times highest compared to three and six layers of neat fabrics respectively.

On the application of additive manufacturing methods for auxetic structures: a review

Auxetic structures are a special class of structural components that exhibit a negative Poisson’s ratio(NPR)because of their constituent materials,internal microstructure,or structural geometry.To realize such structures,specialized manufacturing processes are required to achieve a dimensional accuracy,reduction of material wastage,and a quicker fabrication.Hence,additive manufacturing(AM)techniques play a pivotal role in this context.AM is a layer-wise manufacturing process and builds the structure as per the designed geometry with appreciable precision and accuracy.Hence,it is extremely beneficial to fabricate auxetic structures using AM,which is otherwise a tedious and expensive task.In this study,a detailed discussion of the various AM techniques used in the fabrication of auxetic structures is presented.The advancements and advantages put forward by the AM domain have offered a plethora of opportunities for the fabrication and development of unconventional structures.Therefore,the authors have attempted to provide a meaningful encapsulation and a detailed discussion of the most recent of such advancements pertaining to auxetic structures.The article opens with a brief history of the growth of auxetic materials and later auxetic structures.Subsequently,discussions centering on the different AM techniques employed for the realization of auxetic structures are conducted.The basic principle,advantages,and disadvantages of these processes are discussed to provide an in-depth understanding of the current level of research.Furthermore,the performance of some of the prominent auxetic structures realized through these methods is discussed to compare their benefits and shortcomings.In addition,the influences of geometric and process parameters on such structures are evaluated through a comprehensive review to assess their feasibility for the later-mentioned applications.Finally,valuable insights into the applications,limitations,and prospects of AM for auxetic structures are provided to enable the readers to gauge the vitality of such manufacturing as a production method.