i-manager's Journal on Structural Engineering (JSTE)


Volume 7 Issue 3 September - November 2018

Research Paper

Effect of Boundary Conditions on Modal Analysis of Aluminum Plates Using Digital Image Correlation Technique

Durga Charan* , S. K. Mangal**, Navin Kumar***
* Assistant Professor, Department of Mechanical Engineering, Seth Jai Parkash Mukand Lal Institute of Engineering and Technology, Radaur, Haryana, India.
** Professor, Department of Mechanical Engineering, Punjab Engineering College, Chandigarh, India.
*** Associate Professor, Department of Mechanical Engineering, Indian Institute of Technology, Ropar, Punjab, India.
Charan, D., Mangal, S. K., & Kumar, N. (2018). Effect of Boundary Conditions on Modal Analysis of Aluminum Plates Using Digital Image Correlation Technique, i-manager's Journal on Structural Engineering, 7(3), 1-11. https://doi.org/10.26634/jste.7.3.14750

Abstract

In engineering systems, components are usually subjected to dynamic loading, where resonance may take place. The resulting vibration due to the resonance is of great concern as it may lead to premature failure of the system. Hence, modal analysis of a structure becomes very necessary to know the response characteristics of a system under dynamic loading and also to avoid the resonance conditions during its operation. The objective of this paper is to study the dynamic response of rectangular and circular plates with all edge fixed and all edge free boundary conditions. The natural frequencies and mode shapes are determined using ANSYS software, which has been validated by experimental investigation. The experimentation is carried out on electrodynamic shaker using Digital Image Correlation (DIC) technique. This work has established that different boundary conditions has considerable effect on the system natural frequencies. The maximum deformation of the rectangular plates in all edge fixed boundary conditions has found to have decreasing trend for higher natural frequencies while for same plate in all edge free boundary conditions, an increasing trend is observed for higher natural frequencies. For circular plates in both boundary conditions, i.e. all edge fixed and all edge free boundary conditions, the maximum deformation of aluminum has found increasing trend for higher natural frequencies.

Research Paper

Behavior of Long Carbon Fiber Reinforced Concrete Column to Explosive Loading

Sudhindra Yeri* , S. A. Kambali**, Santosh M. Muranal***
* Lecturer, Department of Civil Engineering, Government Polytechnic, Bagalkot, Karnataka, India.
** Assistant Professor, Department of Civil Engineering, Basaveshwar Engineering College, Bagalkot, Karnataka, India.
*** Professor, Department of Civil Engineering, Basaveshwar Engineering College, Bagalkot, Karnataka, India.
Yeri, S., Kambali, & S. A., Muranal, S. (2018). Behavior of Long Carbon Fiber Reinforced Concrete Column to Explosive Loading, i-manager's Journal on Structural Engineering, 7(3), 12-19. https://doi.org/10.26634/jste.7.3.14032

Abstract

In view of increasing threats of explosion from accidental and terrorists attack, the design of exterior column becomes critical as explosive load sometime exceed the design lateral seismic load. The columns which are vulnerable to explosive load are needed to strengthen in flexure and shear capacity. The closely spaced ties in the plastic hinge region confine the core concrete and resist the buckling of longitudinal reinforcement. Hence the adequacy of column reinforced according to IS 13920-2016 in resisting the blast load is numerically simulated in this study. The Fiber Reinforced Concrete (FRC) may enhance the shear and flexural resistance. The Long Carbon Fiber Reinforced Concrete (LCFRC) column for explosive loads is modeled in Finite Element (FE) software LS-DYNA. The result shows that the ductile detailed column resulted in improved shear resistance under blast load. The LCFRC columns results in reduced surface damage, cracking of concrete, and deflection. The column reinforced according to IS 13920-2016 and LCFRC column showed greater resistance to explosive load.

Research Paper

Seismic Evaluation and Modelling Techniques for Open Ground Storey Buildings

Pramodini Naik* , Satish Annigeri**
* Head, Department of Civil Engineering, Government Polytechnic, Bicholim, Goa, India.
** Professor, Department of Civil Engineering, KLE Technological University, Hubballi, Karnataka, India.
Naik, P., & Annigeri, S. (2018). Seismic Evaluation and Modelling Techniques for Open Ground Storey Buildings, i-manager's Journal on Structural Engineering, 7(3), 20-31. https://doi.org/10.26634/jste.7.3.14040

Abstract

Failure of Open Ground Storey (OGS) buildings in the past devastating earthquakes like Bhuj, in India (2001) has urged the designers to carry out seismic evaluation of existing buildings and design the new buildings to withstand major earthquakes without collapse. Pushover analysis is the most commonly adopted analytical approach for seismic performance evaluation, the accuracy of which lies in suitable modeling assumptions made. In this paper, an effort is made to arrive at a definite modeling strategy to be adopted for the typical OGS building system while performing Nonlinear Static Pushover (NSP) analysis. Three building models representing the lateral stiffness of the building were considered, namely OGS bare frame (model 1), OGS within fill stiffness consideration in the upper storeys (model 2), building with infill stiffness consideration in the upper storey's and modeling additional infill stiffness in the corner bays of OGS (model 3). Lateral load analysis was considered for two cases, namely ESA (Equivalent Static Analysis) and RSA (Response Spectrum Analysis). For modeling the lateral load and nonlinear hinge properties, four scenarios were considered, scenario-1 with ESA load pattern and default hinges, Scenario 2 – RSA and user defined hinges, Scenario 3 – ESA and user defined hinges, and Scenario 4 - RSA with user defined hinges. The findings of the study revealed that the commonly adopted “model 1 – scenario 1” criteria results in an inaccurate prediction of performance levels of demand earthquake. Amongst the three models studied, model 3 shows the highest base shear by about two times and lowest roof displacement (60%) compared to bare frame and hinge status in case of scenario 1 is overestimated compared to scenarios 2 to 4. Therefore, model 3-scenario 4 is a better modeling strategy among the three models studied.

Research Paper

Seismic Stability of Combined Conical Elevated Water Tanks Under Varying Water Percentage in Conical and Cylindrical Parts

Syed Shafahaduddin Quadri* , R. M. Sawant**
* Assistant Professor, Department of Civil Engineering, Maharashtra Institute of Technology, Aurangabad, Maharashtra, India.
** Professor, Department of Civil Engineering, P. E. S. College of Engineering, Aurangabad, Maharashtra, India.
Quadri, S. S., & Sawant, R. M. (2018). Seismic Stability of Combined Conical Elevated Water Tanks under Varying Water Percentage in Conical and Cylindrical Parts, i-manager's Journal on Structural Engineering, 7(3), 32-41. https://doi.org/10.26634/jste.7.3.14107

Abstract

Combined conical elevated water tanks are widely used as water reservoirs in various locations around the world.Current Indian codes of practice do not provide any provisions or guidelines for the analysis and design of reinforcedconcrete Combined conical elevated water tanks under hydrostatic loading. Available codes provisions are limitedonly for the design of cylindrical and rectangular tanks. The present study investigates the behavior of combined conicalelevated water tank under varying water percentage in conical and cylindrical parts by performing dynamic analysis,i.e. Response Spectrum method. The main aim of this research work is to find out the optimum water percentage inconical and cylindrical part for combined conical elevated water tank. The modeling and analysis of combinedconical elevated water tank is carried out by using structural analysis and design computer program, i.e. STAAD.Pro. Totaltwenty number of models were made for empty tank and full tank condition, where these models are provided with tencolumns along with the periphery of a circle with five staging levels and connected by using Cross Stagingpattern. The responses of each combined conical elevated water tank are represented graphically.

Research Paper

Mechanical Properties of Fibre Reinforced Alkali- Activated Concrete

Sonal Thakkar* , Urmil Dave**, Kush Shah***
* Research Scholar & Assistant Professor, Department of Civil Engineering, Institute of Technology, Nirma University, Gujarat, India.
** Professor, Department of Civil Engineering, Institute of Technology, Nirma University, Gujarat, India.
*** Post-graduate, Department of Civil Engineering, Institute of Technology, Nirma University, Gujarat, India.
Thakkar, S., Dave, U., & Shah, K. (2018). Mechanical Properties of Fibre Reinforced Alkali- Activated Concrete, i-manager's Journal on Structural Engineering, 7(3), 42-50. https://doi.org/10.26634/jste.7.3.13988

Abstract

In the modern era, where sustainable concrete is a buzzword, all efforts are made to find a substituteof cement. Fly ash basedalkali-activated concreteis one of sustainable solutions in place of Ordinary Portland Cement concrete. This concrete uses industrial waste as one of the constituents in the concrete and thus offers sustainable solution to waste disposal and also has a very high early strength. The present investigation has studied the effect of polypropylene fibresinalkali-activated concrete. To understand the behaviour of fibre reinforced alkali-activated concrete, mechanical properties like compressive strength, flexural strength, split tensile strength, modulus of elasticity, and bond strength were investigated. Comparison of these results was carried out with fibre reinforced ordinary Portland cement concrete to evaluate the behaviour of fibre reinforced alkali-activated concrete. It was observed that with the addition of polypropylene fibres, 7 days strength in compression increased by 72%, in flexure by 35%, in modulus of elasticity by 42%, and in bond by 10% compared to Ordinary Portland Cement concrete with fibres. Thus, for high early strength alkali-activated concrete with polypropylene fibre becomes more suitable.