Bibhu Mohanty - Academia.edu (original) (raw)

Papers by Bibhu Mohanty

Research paper thumbnail of Numerical investigation of blasting-induced damage in cylindrical rocks

International Journal of Rock Mechanics and Mining Sciences, 2008

In order to investigate rock fracture and fragmentation mechanisms under dynamic loading, a cylin... more In order to investigate rock fracture and fragmentation mechanisms under dynamic loading, a cylindrical rock model with a centralized borehole is developed through the use of AUTODYN code. According to the material properties and loading conditions, four kinds of equation of state (EOS), linear, shock, compaction and ideal gas, are applied to the four kinds of materials employed in this numerical model. A modified principal stress failure criterion is applied to determining material status, and a well-behaved explosive, PETN, and a relatively homogeneous igneous rock, diorite, are used in this rock model. A single centrally located line source of explosive is fired numerically to produce the dynamic loadings operating on the surrounding rocks. This numerical model is applied to actual blasting conditions. The rock failure mechanism under dynamic loading is first analyzed, and then the influences of the following factors on rock fracturing are discussed: (a) coupling medium, (b) confinement, (c) boundary condition, (d) initiation location in an explosive column, and (e) air ducking. The results show that all these factors have significant effects on rock fracturing under dynamic loading. r

Research paper thumbnail of Numerical investigation of blasting-induced crack initiation and propagation in rocks

International Journal of Rock Mechanics and Mining Sciences, 2007

To investigate the dynamic fracture mechanism related to blast-induced borehole breakdown and cra... more To investigate the dynamic fracture mechanism related to blast-induced borehole breakdown and crack propagation, circular rock models containing a single centrally located source of explosive were numerically blasted using the AUTODYN 2D code. According to the material properties and loading conditions, four kinds of equations of state, linear, shock, compaction and ideal gas, are used. A modified principal stress failure criterion is applied to determining material status. The dynamic stresses at the selected target points in a rock sample are computed as a function of time following application of explosive load. It is shown that shear stress (resulting from intense compressive stress) causes a crushed zone near the borehole, the major tensile principal stress causes radial cracks, and the reflected stress wave from free boundary causes circumferential cracks some distance away from the free boundary. The influences of the factors of boundary condition, coupling medium, borehole diameter, decoupling and joint on rock dynamic fracture are discussed. r

Research paper thumbnail of Transformation of Social Responsibility of Corporate bodies from voluntary to statutory condition: -A discussion

Recent changes in Company Bill of India have created a heavy jolt on corporate bodies to act seri... more Recent changes in Company Bill of India have created a heavy jolt on corporate bodies to act seriously on social responsibility. It is known to all that people with good richness usually practice philanthropy activities in terms of religious activities, simple giving to needy people, donations to institutions and so on. In last decade of last millennium MOEF, Govt of India started instructing the companies along with the environmental clearance to get involved in development of environmental , social and economic wellbeing of people / communities around the corporate bodies. In this the weakness of lack of strong monitoring system , lack of clarity on spending towards such activities and lack of clarity and commitment of business houses could not make serious and uniform impact on Indian economy. Recent changes in Company Bill ensure outstanding and long term impact on people aspired areas of development. Looking into above evolution of practicing socio-economic development by the existing corporate organizations there are many challenges before them as they will be directly implementing many of the development activities in this country. There are several issues like setting organization or team dedicated to this work, professional manpower deployment, design of annual business plan, social audit of the work done and success claimed and identifying the real area of concern etc. This paper has tried to discuss on the evolution of CSR activities in India.

Research paper thumbnail of Numerical investigation of blasting-induced damage in cylindrical rocks

International Journal of Rock Mechanics and Mining Sciences, 2008

In order to investigate rock fracture and fragmentation mechanisms under dynamic loading, a cylin... more In order to investigate rock fracture and fragmentation mechanisms under dynamic loading, a cylindrical rock model with a centralized borehole is developed through the use of AUTODYN code. According to the material properties and loading conditions, four kinds of equation of state (EOS), linear, shock, compaction and ideal gas, are applied to the four kinds of materials employed in this numerical model. A modified principal stress failure criterion is applied to determining material status, and a well-behaved explosive, PETN, and a relatively homogeneous igneous rock, diorite, are used in this rock model. A single centrally located line source of explosive is fired numerically to produce the dynamic loadings operating on the surrounding rocks. This numerical model is applied to actual blasting conditions. The rock failure mechanism under dynamic loading is first analyzed, and then the influences of the following factors on rock fracturing are discussed: (a) coupling medium, (b) confinement, (c) boundary condition, (d) initiation location in an explosive column, and (e) air ducking. The results show that all these factors have significant effects on rock fracturing under dynamic loading. r

Research paper thumbnail of Numerical investigation of blasting-induced crack initiation and propagation in rocks

International Journal of Rock Mechanics and Mining Sciences, 2007

To investigate the dynamic fracture mechanism related to blast-induced borehole breakdown and cra... more To investigate the dynamic fracture mechanism related to blast-induced borehole breakdown and crack propagation, circular rock models containing a single centrally located source of explosive were numerically blasted using the AUTODYN 2D code. According to the material properties and loading conditions, four kinds of equations of state, linear, shock, compaction and ideal gas, are used. A modified principal stress failure criterion is applied to determining material status. The dynamic stresses at the selected target points in a rock sample are computed as a function of time following application of explosive load. It is shown that shear stress (resulting from intense compressive stress) causes a crushed zone near the borehole, the major tensile principal stress causes radial cracks, and the reflected stress wave from free boundary causes circumferential cracks some distance away from the free boundary. The influences of the factors of boundary condition, coupling medium, borehole diameter, decoupling and joint on rock dynamic fracture are discussed. r

Research paper thumbnail of Transformation of Social Responsibility of Corporate bodies from voluntary to statutory condition: -A discussion

Recent changes in Company Bill of India have created a heavy jolt on corporate bodies to act seri... more Recent changes in Company Bill of India have created a heavy jolt on corporate bodies to act seriously on social responsibility. It is known to all that people with good richness usually practice philanthropy activities in terms of religious activities, simple giving to needy people, donations to institutions and so on. In last decade of last millennium MOEF, Govt of India started instructing the companies along with the environmental clearance to get involved in development of environmental , social and economic wellbeing of people / communities around the corporate bodies. In this the weakness of lack of strong monitoring system , lack of clarity on spending towards such activities and lack of clarity and commitment of business houses could not make serious and uniform impact on Indian economy. Recent changes in Company Bill ensure outstanding and long term impact on people aspired areas of development. Looking into above evolution of practicing socio-economic development by the existing corporate organizations there are many challenges before them as they will be directly implementing many of the development activities in this country. There are several issues like setting organization or team dedicated to this work, professional manpower deployment, design of annual business plan, social audit of the work done and success claimed and identifying the real area of concern etc. This paper has tried to discuss on the evolution of CSR activities in India.