Pramendra Kumar Bajpai

Hole making in natural fiber-reinforced polylactic acid laminates: An experimental investigation

Natural fiber-reinforced composite materials are finding wide acceptability in various engineering applications. A substantial increase in the volume of production of these composites necessitates high-quality cost-effective manufacturing. Drilling of holes is an important machining operation required to ascertain the assembly operations of intricate composite products. In the present experimental investigation, natural fiber (sisal and Grewia optiva fiber)-reinforced polylactic acid-based green composite laminates were developed using hot compression through film stacking method. The drilling behavior of green composite laminates was evaluated in terms of drilling forces (thrust force and torque) and drilling-induced damage. The cutting speed, feed rate, and the drill geometry were taken as the input process parameters. It was concluded that all the three input process parameters affect the drilling behavior of green composite laminates. The drill geometry was established as an important input parameter that affects the drilling forces and subsequently the drilling-induced damage.

Studies on Mechanical and Morphological Characterization of Developed Jute/Hemp/Flax Reinforced Hybrid Composites for Structural Applications

ABSTRACT In the present study, an attempt has been made to develop and characterize natural fiber-based composites (jute/epoxy, hemp/epoxy, flax/epoxy) and their hybrid composites (jute/hemp/epoxy, hemp/flax/epoxy, and jute/hemp/flax/epoxy) using hand-lay-up technique. Mechanical characterization (tensile, flexural, impact, and hardness test) of the developed composites was performed. The interface between fiber and matrix was examined using scan electron microscopy (SEM). Among (jute/epoxy, hemp/epoxy, flax/epoxy), flax/epoxy composite has shown higher hardness (98 Shore-D) and tensile strength (46.2 MPa) whereas better flexural and impact strength have been shown by hemp/epoxy (85.59 MPa) and jute/epoxy (7.68 kJ/m2) composites respectively. Results showed that hybrid composites observed better mechanical properties. Jute/hemp/flax/epoxy hybrid composite showed the highest tensile strength, modulus and impact strength of 58.59 MPa, 1.88 GPa, and 10.19, kJ/m2, respectively. Jute/hemp/epoxy hybrid composite achieved the maximum flexural strength of 86.6 MPa.

Effect of moisture absorption on the mechanical performance of natural fiber reinforced woven hybrid bio-composites

ABSTRACT In the present study, moisture uptake behavior and their effect on mechanical properties of plant fibers were investigated while these fibers were reinforced with epoxy matrix. The developed composites were dipped in tap water for a span of 12 months at room temperature. Hardness (shore-D), tensile, and flexural properties were evaluated after 1 year immersion of samples in water and compared with that of the dry specimens. Water saturated jute/hemp/epoxy composite specimen showed the highest reduction in tensile strength and young’s modulus by 46.9% and 51.8%, respectively. Water saturated hemp/epoxy composite specimen showed the highest reduction in flexural strength by 45.1%. Highest reduction of 39.7% in the flexural modulus was achieved by the jute/hemp/epoxy composite specimen. Hardness had observed no significant decrease in the values due to moisture absorption. scanning electron microscopy images of fractured surfaces of these bio-composites showed quite relevant information regarding weakening of fiber/matrix interface.

FEM Analysis of Glass/Epoxy Composite Based Industrial Safety Helmet

Recently, the use of fiber reinforced polymer in every field of engineering (automobile, industry and aerospace) and medical has increased due to its distinctive mechanical properties. The fiber based polymer composites are more popular because these have high strength, light in weight, low cost and easily available. In the present work, the finite element analysis (FEA) of glass/epoxy composite based industrial safety helmet has been performed using solid-works simulation software. The modeling results show that glass fiber reinforced epoxy composite can be used as a material for fabrication of industrial safety helmet which has good mechanical properties than the existing helmet material.

Analysis of Wear Behavior of Thermoplastic Bio-Composite

In the present work, response surface methodology (RSM) has been used to model and predict the wear properties of Bio-composites fabricated in this study. Polished stainless steel counterface has been used to analyze the wear response of the bio-composite under dry contact condition. Three process variables namely applied sliding speed, normal load, and sliding distance were taken to investigate their effect on output response (specific wear rate). Statistical analysis was performed in the form of the analysis of variance (ANOVA) to analyze the significance and interaction of experimental parameters. The mathematical relationship between sliding wear input process parameters and output responses has been established to determine the values of output responses.