Research Publications

Selected Publications:

Project: Modelling of Instabilities in Soft Tissues

The research activities that have been conducted concern with the novel development of formulations and numerical implementation of hyperelastic material models that include the effect of residual stress fields following an invariant-based approach. These activities have been developed within the context of the Project MAT2015-71036-P funded by the Spanish Ministry of Economy and Competitiveness/FEDER. Project was aimed at i) understanding the role of residual stresses in bifurcation of solids ii) enabling improved description of growth/softening by means of constitutive modeling.

Co-workers: Jose Reinoso (University of Seville), Jose Merodio (UP Madrid)

Publications:

1. D. Desena-Galarza, H. Dehghani, N. K. Jha, J. Reinoso, J. Merodio

Computational bifurcation analysis for hyperelastic residually stressed tubes under combined inflation and extension and aneurysms in arterial tissue, Finite Elements in Analysis & Design, 2021 (Under Review)

2. Alejandro Font, Niraj Kumar Jha, H. Dehghani, J. Reinoso, J. Merodio
   Modelling of residually stressed, extended and inflated cylinders with application to aneurysms", Mechanics Research Communication, 2020

3. Niraj Kumar Jha, Jose Merodio, Jose Reinoso
   ``A general non-local constitutive relation for residually stressed solids", Mechanics Research Communication, 2019

4. Hamidreza Dehghani, D. Desena-Galarza, Niraj Kumar Jha, Jose Merodio, Jose Reinoso

``Modelling bifurcation and post-bifurcation of an inflated and extended residually-stressed circular cylindrical tube with application to aneurysms initiation and propagation in arterial wall tissue", Finite Elements in Analysis and Design, 2019

5. Niraj Kumar Jha, Jose Reinoso, Hamidreza Dehghani, Jose Merodio,
``Constitutive modelling of residually stressed viscoelastic solid", Mechanics Research Communication, 2019

6. Niraj Kumar Jha, Jose Reinoso, Hamidreza Dehghani, Jose Merodio,
``A computational model for cord-reinforced rubber composites: hyperelastic constitutive formulation including residual stresses", Computational Mechanics, 2019

Project: Modelling and numerical simulation for the prediction of the fatigue strength of airspring

This research investigates the mechanical response of airsprings by means of two length scales macro and submodel or mesoscale. The macro-scale analysis is performed under quasi-static loading condition and smeared rebar technique is applied for the cord reinforcement whereas meso-mechanical analysis considers the dimension of cords, rubber at the order of reinforcement. Overall aim of the project was to develop a framework for three distinct problems at hand : (i) damage law suitable for rubber matrix considering strong interface between matrix and interface (ii) bulk rubber matrix as mentioned previously but with a weak interface that derives a novel Progressive Damage Analysis (PDA) methodolgy and (iii) anisotropic hyperelastic model considering for a residually stressed airspring at the macroscale. These activities have been developed within the context of the Project funded by Continental Hannover.

Co-workers: Udo Nackenhorst (Leibniz University of Hannover), P.J. Guruprasad (IIT Bombay)

Publications:

1. Niraj Kumar Jha, Udo Nackenhorst, Vaibhav Pawar, Rajesh Nadella, PJ Guruprasad,
``On the constitutive modelling of damage in rubber-like materials", International Journal of Solids and Structures, 2019

2. Niraj Kumar Jha
Modeling and numerical simulation for the prediction of the fatigue strength of airsprings , ISBN - 9783935732468, Publisher: Institut für Baumechanik und Numerische Mechanik, Gottfried Wilhelm Leibniz Universität Hannover

3. Niraj Kumar Jha and Udo Nackenhorst,
``Fatigue life prediction of cord-rubber structure using progressive damage analysis", Engineering Computation, 2018

4. Niraj Kumar Jha and Udo Nackenhorst,
"A continuum damage modeling of quasi-static strength of cord-reinforced rubber airspring ". 10th European Conference on Constitutive Models for Rubbers (2017)

5. Niraj Kumar Jha , U. Nackenhorst , T. Helmich and C. Lillie,
"A non-local approach to life time prediction of cord-rubber composite structure " ECCOMAS Congress 2016

6. Niraj Kumar Jha and Udo Nackenhorst,
"Fatigue mechanisms of cord–rubber composites." PAMM 15, no. 1 (2015)

Project: Phase Field Methods for Composites

This research proposes an invariant-based pressure-dependent phenomenological elasto-plastic material model with non-associative anisotropic plastic evolution is consistently coupled with the phase field approach for ductile fracture.

Co-workers: Aamir Dean (Leibniz University of Hannover), Jose Reinoso (University of Seville)

Publications:

1. A. Dean, J. Reinoso, N.K. Jha, E. Mahdid, R. Rolfes
``A phase field approach for ductile fracture of short fibre reinforced composites". Theoretical and Applied Fracture Mechanics , 2020

Project: Sensitivity Analysis

Global sensitivity analysis provides a direct way of assessing the relative contribution to the overall uncertainty from each input parameter in conjunction with the so-called Morris method in order to identify the representativeness of the parameters of the system. Through the exploitation of a simple sensitivity analysis, it is possible to determine the more representative parameters of the system.

Publications:

1. Niraj Kumar Jha
``On the Sensitivity Analysis of Residually Stressed Constitutive Model". ICRACEM 2020: Recent Advances in Computational and Experimental Mechanics

2. Pandi Pitchai, Niraj Kumar Jha, Rajeev G.Nair, P. J. Guruprasad

"A coupled framework of variational asymptotic method based homogenization technique and Monte Carlo approach for the uncertainity and sensitivity analysis of unidirectional composites" . Composite Structures, 2020 (Under Review)

Project: Tyre Dynamics and NVH

The subprojects under this category is a mix of experimental and numerical approach. It details noise and vibration due to various tyre design related parameters.

Publications:

1. Niraj Kumar Jha et al.

"Influence of mechanical wear on tyre noise ". INTER-NOISE and NOISE-CON Congress and Conference Proceedings. Vol. 259. No. 7. Institute of Noise Control Engineering, 2019

2. Vipul Paliwal , Ritvik Dobriyal, Pushpendra Kumar, Niraj Kumar Jha

"Quarter Car Model with Power Law Damper Excited by a Road Profile ". Lecture Notes in Mechanical Engineering, Proceedings of FLAME 2020

3. Ritvik Dobriyal, Pushpendra Kumar, Niraj Kumar Jha, Vipul Paliwal, Prateek Negi

"Dynamics and Optimization of a Quarter Car Model with Power Law Spring ", Indian Journal of Engineering and Material Science , 2021 (Under Review)

4. Niraj Kumar Jha et al.

"Effect of Tyre Imperfection on Vehicle Response", Tire Science and Technology (Virtual Conference), 2020 (Under Review)

Selected Presentations:

1. Fatigue mechanisms of cord-rubber composites, GAMM Leece, 2015 Gamm_2015

2. A non-local approach to lifetime prediction of cord-rubber composite, ECOMMAS Creta, 2016 ECOMMAS_2016

3. Progressive damage modelling of Airspring: An Overview, EuroMech Porto, 2016 EuroMech_2016

4. Fatigue damage modelling of Airspring: An Overview, ECCMR Munich, 2017 ECCMR_2017

5. Influence of mechanical wear on tyre noise, Internoise Madrid, 2019 Internoise_2019

6. Effect of tyre and steering design parameters on vehicle handling test, MSC Bangalore, 2019, MSC_2019

7. Application of residual stress in tyre, Tire Technology International, 2019 TTI_2019

8. On the sensitivity analysis of residually stressed constitutive model, 2020 ICRACEM_2020

9. Effect of tyre imperfection on vehicle response, TST 2020 TST_2020

10. Ride Assessment of a Passenger Car under various Road Conditions , MSC 2020 MSC_2020