Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

The performance of novel Layered Two Stage Fibrous Composite slabs (LTSFC) was pioneered under falling mass collisions using a combined experimental and numerical study. Such LTSFC slabs consist of three layers with and without the insertion of glass fibre mesh between the layers. LTSFC techniques were used to fabricate the composite slabs with three layers including 3%, 1.5%, and 3% of fibre content for the top, middle, and bottom layers respectively. Sixteen MLPAFC square slabs were cast with only short hooked end fibres and tested under falling mass collisions by amending two parameters namely the type of support (fixed and hinge) and support layout. Two distinct support layouts on two types of support were considered and tested with and without the glass fibre mesh between layers of LTSFC. A glass fibre mesh was introduced between the three layers to block crack growth propagation and absorb additional collision energy. The glass fibre mesh insertion between the layers and the LTSFC production technique were considered as novel modifications. A numerical study using Auto desk Fusion 360 was conducted and compared with experimental results. The numerical results showed fair agreement with the experimental test results. Based on the validated numerical models, collision energy and cracking pattern evolution were studied. The findings indicated that the glass fibre mesh insertion between the layers combined with steel fibres disrupted crack proliferation, thus exhibiting superior engrossed collision energy and postponing crack growth. Additionally, the engrossed collision energy at crack initiation and ultimate crack for the slabs with four sides fixed and hinged support were greater with respect to two opposite sides fixed and hinged support. Numerical values were in reasonable agreement with the experimental values in terms of collision energy and cracking patterns. © 2020

World University root node

Civil

School of Civil Engineering

Chennai Campus

Structures

Impact response of novel layered two stage fibrous composite slabs with different support type

This research aimed to study the impact response of topology optimized hammerhead pier beam (HPB) based on the density approach. The HPB is prepared with the concept of preplaced aggregate fibrous concrete (PAFC) comprising two primary approaches; first, the coarse aggregate and fiber are prepacked into the designed formwork. Second, the gaps between the aggregate and fiber are filled with cement grout. In this work, an attempt has been made to study an impact response of HPB made with PAFC. Five HPBs were prepared and strengthened with steel fibers with two different schemes, Firstly, the HPB was reinforced with a full cross-section at 2 and 4% of steel fiber, while another set of beams were only reinforced in the tension zone with the same amount of fibers. The study parameters included compressive strength, impact strength, impact ductility index, number of main and secondary cracks, and failure pattern. It was observed that the PAFC had an increase in compressive strength up to 56.9%, compared with nonfibred concrete. A fully fibered concrete beam with 4% fiber addition was the best at taking impact, and the initial crack and failures were observed at 2725.1 J and 3009.8 J, respectively, compared with non-fibered and tension zone fibered concrete beams. Compressive local damage and transverse flexural cracks were observed, which had caused initial cracks and final failure. The HPB with a full reinforced scheme at 4% dosage exhibited higher impact strength than the normal concrete and beam reinforced only in the tension zone. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Crystals

Impact response of preplaced aggregate fibrous concrete hammerhead pier beam designed with topology optimization

In the course of global terrorist events prominent risks were faced by military and civilian infrastructure. Subsequently, the design of structures to resist impact load has become vital in the design process. Fibre reinforced polymer sheets were utilized as exceptional material to enhance the resistance of the structure to impact load. Until now, most researchers focused on the response of Fibre Reinforced Polymer (FRP) strengthened slabs under static load. Extensive research on the impact response of FRP strips strengthened slabs is relatively rare and the outcome of these investigations have been controversial. Therefore, it is vital to comprehend the response of FRP strengthened slabs subjected to falling mass collisions. In this study, impact response of Glass Fibre Reinforced Polymer (GFRP) strips strengthened Two Stage Reinforced Concrete Slabs (TSRCS) have been examined through experiments. Two different widths of 50 mm and 75 mm GFRP strips were used in perpendicular and oblique ways in one and two directions while strengthening TSRCS. In Total, a nine 1,000 mm × 1,000 mm × 60 mm TSRCS were fabricated and later impacted by a steel cylinder of 55 kg dropping at the centre from a 3,000 mm height. Study parameters analysed to discover the impact response of TSRCS include, impact-force history, acceleration, damaged area (top and bottom face), damage area ratio, damage volume ratio, and damage pattern. The results revealed that the slab strengthened with 75 mm GFRP strips was more effective in alleviating damage volume ratio compared to the 50 mm GFRP strips. Also, the obtained results in this study shed light on the impact performance of two stage reinforced concrete slabs. © 2020, Korean Society of Civil Engineers.

Department of Mathematics

School of Advanced Sciences

Vellore Campus

KSCE Journal of Civil Engineering

Experimental Study on GFRP Strips Strengthened New Two Stage Concrete Slabs under Falling Mass Collisions

Recently, a numerous topology optimization technique has been reported by the earlier researchers. Within most techniques, a design domain with applied boundary conditions and load case is well defined and used by the design engineers. The design problems in formal optimization problem are rigorously solved using a mathematical program. To the judicious understanding of authors, an optimization through a density-based approach is still in infancy and there only exists limited literature. In this study, a density-based topology-optimized design of plain concrete hammerhead beams was investigated using Autodesk Fusion 360. For this intention, the design example from the literature has been used for topology optimization. Imposing stress limits on the design problem considered in this work is found to create solutions that require significant levels of post-processing prior to construction. The results revealed that the size lessening without affecting its functionality led to saving in building materials within the built world. Also, an interactive density-based topology optimization of concrete beams resulted in new shapes and topology of beams for use in the bridge construction industry. © 2021, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

Lecture Notes in Civil Engineering

A Simple Approach for Topological Optimization of Concrete Beams

This study aims to study topology Optimized Hammerhead Pier Beam (TOHPB) designed with a density-based technique. TOHPB is made with Preplaced Aggregate Fibrous Concrete (PAFC), which comprises two main preparation processes. First, the fibers and coarse aggregates filled into empty formwork to develop a skeletal system. Second, voids in the skeletal system are filled with cement grout; hence a type of PAFC was obtained. Besides, alleviating the self-weight of the concrete beam is a top priority of design engineering without compromising its strength and durability. The effect of topology optimization in association with the safety of factors and elastic design case is considered in this study. Explicitly, (i) compliance is scaled down to a minimum under a perimeter on the utilized material (ii) the principle Drucker-Prager is employed to impose the stress limitations even though utilization of material is minimized. The problem is designed with imposed stress limitation and generates keys that involve an essential part of post-processing before fabrication. In total, ten TOHPB were prepared with and without the combined shape of crimped-hooked end steel fiber. Two different types of fiber reinforcement schemes were used; first, the fibers were reinforced to full beam cross-section; then, the fibers were reinforced to the top half of the beam cross-section. Results revealed that the TOHPB beam reinforced full cross-section exhibited better ultimate load performance than that of the beam with half reinforced cross-section. © 2020, Budapest University of Technology and Economics. All rights reserved.

Periodica Polytechnica Civil Engineering

Study of topology optimized hammerhead pier beam made with novel preplaced aggregate fibrous concrete

The Multi-layer Two Stage Fibrous Composite (MTSFC) is an innovative type of composite that has gained popularity in recent years and pulled the attention of researchers on global level. The process of preparation composes the subsequent two key actions; first, the natural coarse aggregate skeleton is formed by piling the coarse aggregates and fibres in a particular way; second, the artificially formed skeleton is fully filled with cement grout by gravity method. In the present study, the effect of Glass Fibre Mesh (GFM) insertion on MTSFC is researched by subjecting to falling mass and projectile impacts. Totally, twenty one mixtures with insertion of GFM of varied diameters and with different layout in between the layers are designed and tested under falling mass and projectile impacts. Additionally, the hooked end fibre at a dosage of 2.5% volume of composite was constantly used for all designed mixtures. The purpose of inserting glass fibre mesh in between the top-middle and middle-bottom layer is to play a role of trapping layer in order to prevent/delay the crack propagation. The multiple number of hits to provoke crack initiation and crack ultimate, impact energy at crack initiation and crack ultimate, impact ductility index, front damage area, bottom damage area, damage ratio, depth of penetration and damage pattern are studied hereby. The findings revealed that the GFM reinforcement stratagem combined with steel fibres in MTSFC, turned out to deliver high resistance against impact load and extends the failure duration by absorbing more energy. Also, findings indicated that the depth of penetration, damage area and damage ratio were raised with the number of hits and were lessened by the high content steel fibres together with GFM and coarse aggregate. Consequently, the effect of GFM insertion is minimal when it is placed inbetween top-middle layer. Preferably, it is best to insert GFM inbetween mid-bottom layer in the MTSFC, which extends to delay the crack proliferation while tensile stress are being transformed and offers more impact energy absorbance. The research outcomes obtained from this study is to deliver a baseline information for continuing a deeper research work on MTSFC under impact. © 2020 Elsevier Ltd

Construction and Building Materials

Multi-layered two stage fibrous composites against low-velocity falling mass and projectile impact

Steel fenders are frequently employed in bridge pier shields to engross collision energy due to vessel impact. However, vulnerability to corrosion is a major drawback in existing steel fenders. To end this, an innovative composite fender structure consisting of corrugated steel and Preplaced Aggregate Fibre Reinforced Concrete (PAFRC) is introduced. Corrugated plates of steel are intended to absorb energy and stiff guard outer panels made with PAFRC exhibit enhanced resistance to impact and ductility. Six steel-PAFRC fenders were prepared with the steel plates of two different thicknesses, where the four top panels of the PAFRC are reinforced with short and long hooked end steel fibres while bottom panels are made with non-fibrous preplaced aggregate concrete (PAC). All steel-PAFRC fenders were tested through a drop weight impact testing device to investigate their impact behaviour and failure mechanism. Collision energy at crack initiation and the ultimate crack of PAFRC panels, crushing deformation of corrugated plates and failure configuration were also examined. Additionally, a numerical model of composite fenders was developed and verified through experimental evidence. Research revealed the crashworthiness of PAFRC panel was higher when compared to the PAC panel. The relative resistance of corrugated plates of steel and the PAFRC panels had a dramatic effect on the composite fender's impact response. © 2020 Institution of Structural Engineers

A novel steel-PAFRC composite fender for bridge pier protection under low velocity vessel impacts

Reducing the weight of concrete beams is a primary (beyond strength and durability) concern of engineers. Therefore, this research was directed to investigate the impact response of hammerhead pier concrete beams designed with density-based method topology optimization. The finite element topology optimization was conducted using Autodesk fusion 360 considering three different mesh sizes of 7 mm, 10 mm, and adaptive meshing. Three optimized hammerhead beam configurations; HB1, HB2, and HB3, respectively, with volume reductions greater than 50%. In the experimental part of this research, nine beams were cast with identical size and configuration to the optimized beams. Three beams, identical to the optimized beams, were tested under static bending for verification purposes. In comparison, six more beams, as in the preceding three beams but without and with hooked end steel fibers, were tested under repeated impact load. The test results revealed that the highest flexural capacity and impact resistance at crack initiation and failure were recorded for the adaptive mesh beams (HB3 and HB3SF). The failure impact energy and ductility ratio of the beam HB3SF was higher than the beams HB1SF and HB2SF by more than 270%. The results showed that the inclusion of steel fiber duplicated the optimized beam’s impact strength and ductility several times. The failure impact resistance of fibrous beams was higher than their corresponding plain beams by approximately 2300 to4460%, while their impact ductility ratios were higher by 6.0 to 18.1 times. © 2020, Budapest University of Technology and Economics. All rights reserved.

Impact response of hammerhead pier fibrous concrete beams designed with topology optimization

ISBN:978-93-87950-

Structural Design and Drawing

The principle concern of this study is to assess solar absorption coefficient over solar cladding on building and to reduce the high room temperature due to the excess solar radiation over the wall. Simulations were carried out on a college building (kings college of engineering) by using the solar analysis in autodesk Formlt 360, finding a energy efficient wall of an building and solar cladding installation carried out over that area and audit the solar absorption coefficient in the solar cladding. As an results to reduce the room temperature which also decreasing the energy usage by minimizing the usage of fans and leads to a get an sustainable solar energy from solar cladding, by production of renewable energy form solar cladding it reduce the CO2emission which are generated during the production of energy from fossil fuels. © Medwell Journals, 2017.