About

Romesh Batra is a University Distinguished Professor and Clifton C. Garvin Professor in the Department of Mechanical Engineering at Virginia Tech. His research interests encompass a broad range of topics within mechanics of materials and structural analysis, including material and structural instabilities such as adiabatic shear banding, buckling, and thermo-elasto-visco-plasticity. He specializes in impact and penetration problems, computational mechanics with finite element and meshless methods, and the design of functionally graded structures through material tailoring and topology optimization. His work also extends to soft materials like rubber-like substances, composites including laminated and sandwich structures, damage initiation and progression, molecular mechanics and dynamics at the atomistic level, smart structures utilizing piezoelectricity, and microelectromechanical systems (MEMS). Batra has made significant contributions to the understanding of these areas through both theoretical and applied research, and his publications are available on Google Scholar.

Research topics

• Structural engineering
• Composite material
• Materials science
• Physics
• Mechanics
• Metallurgy
• Thermodynamics
• Classical mechanics
• Engineering
• Mathematics
• Mathematical analysis

Selected publications

• Comments on “Inflation, extension and torsion analysis of compressible functionally graded hyperelastic tubes” by Maedeh Hajhashemkhani and Mohammad Rahim Hematiyan, Acta Mech 231, 3947–3960 (2020)

  Acta Mechanica · 2025-09-02

  article1st authorCorresponding
  PublisherDOI

• Deep learning reduced order models of vaginal tear propagation

  Journal of the mechanical behavior of biomedical materials/Journal of mechanical behavior of biomedical materials · 2025-06-05 · 1 citations

  article
  PublisherDOI

• Material Tailoring of Linearly Elastic Functionally Graded Rubberlike Cylinders Under Combined Radial Expansion, Extension and Twisting Deformations

  Journal of Elasticity · 2025-07-07 · 1 citations

  articleOpen access1st authorCorresponding

  Abstract The material tailoring problem for a hollow circular cylinder composed of an isotropic, incompressible, and linearly elastic functionally graded material has been analytically analyzed. The cylinder is deformed by torques and axial loads on the end faces, and pressures on its inner and outer surfaces. The cylinder material has one elastic parameter, the shear modulus $\mu \left ( r \right ) $ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>μ</mml:mi> <mml:mrow> <mml:mo>(</mml:mo> <mml:mi>r</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> . For the direct problem it is a known positive and continuously varying function in the radial direction, $r$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>r</mml:mi> </mml:math> . For the inverse problem $\mu \left ( r \right )$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>μ</mml:mi> <mml:mrow> <mml:mo>(</mml:mo> <mml:mi>r</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> is a design variable and is found to provide the desired radial variation of either the strain energy density, $W^{def} (r)$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>W</mml:mi> <mml:mrow> <mml:mi>d</mml:mi> <mml:mi>e</mml:mi> <mml:mi>f</mml:mi> </mml:mrow> </mml:msup> <mml:mo>(</mml:mo> <mml:mi>r</mml:mi> <mml:mo>)</mml:mo> </mml:math> , or the von Mises stress, $\sigma ^{VM} \left ( r \right )$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>σ</mml:mi> <mml:mrow> <mml:mi>V</mml:mi> <mml:mi>M</mml:mi> </mml:mrow> </mml:msup> <mml:mrow> <mml:mo>(</mml:mo> <mml:mi>r</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> , for the given loads and the cylinder geometry. If the three loads are simultaneously varied by a factor $\gamma $ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>γ</mml:mi> </mml:math> then $W^{def} \left ( r \right ) $ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>W</mml:mi> <mml:mrow> <mml:mi>d</mml:mi> <mml:mi>e</mml:mi> <mml:mi>f</mml:mi> </mml:mrow> </mml:msup> <mml:mrow> <mml:mo>(</mml:mo> <mml:mi>r</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> and $\sigma ^{VM} \left ( r \right ) $ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>σ</mml:mi> <mml:mrow> <mml:mi>V</mml:mi> <mml:mi>M</mml:mi> </mml:mrow> </mml:msup> <mml:mrow> <mml:mo>(</mml:mo> <mml:mi>r</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> , respectively, change by $\gamma ^{2} $ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>γ</mml:mi> <mml:mn>2</mml:mn> </mml:msup> </mml:math> and $\gamma $ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>γ</mml:mi> </mml:math> for fixed $\mu \left ( r \right ) $ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>μ</mml:mi> <mml:mrow> <mml:mo>(</mml:mo> <mml:mi>r</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> in the direct problem and $\mu (r)$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>μ</mml:mi> <mml:mo>(</mml:mo> <mml:mi>r</mml:mi> <mml:mo>)</mml:mo> </mml:math> by $\gamma ^{2} $ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>γ</mml:mi> <mml:mn>2</mml:mn> </mml:msup> </mml:math> and $\gamma $ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>γ</mml:mi> </mml:math> in the inverse problem for preassigned $W^{def} (r) = W_{cr} \left ( r \right ) $ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>W</mml:mi> <mml:mrow> <mml:mi>d</mml:mi> <mml:mi>e</mml:mi> <mml:mi>f</mml:mi> </mml:mrow> </mml:msup> <mml:mo>(</mml:mo> <mml:mi>r</mml:mi> <mml:mo>)</mml:mo> <mml:mo>=</mml:mo> <mml:msub> <mml:mi>W</mml:mi> <mml:mrow> <mml:mi>c</mml:mi> <mml:mi>r</mml:mi> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo>(</mml:mo> <mml:mi>r</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> and $\sigma ^{VM} \left ( r \right ) = \sigma _{cr}^{VM} \left ( r \right )$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>σ</mml:mi> <mml:mrow> <mml:mi>V</mml:mi> <mml:mi>M</mml:mi> </mml:mrow> </mml:msup> <mml:mrow> <mml:mo>(</mml:mo> <mml:mi>r</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> <mml:mo>=</mml:mo> <mml:msubsup> <mml:mi>σ</mml:mi> <mml:mrow> <mml:mi>c</mml:mi> <mml:mi>r</mml:mi>

  PublisherOA PDFDOI

• Coupled torsion and inflation of functionally graded and residually stressed Mooney–Rivlin hollow cylinders

  Mathematics and Mechanics of Solids · 2024-09-30 · 6 citations

  article1st authorCorresponding

  Functionally graded structures have material properties continuously varying in one or more directions. Examples include human teeth, sea shells, bamboo stems, and mammal organs in which the varying volume fraction and orientation of fibers optimize their functionalities. Here we analytically study large deformations due to combined torsion and inflation of residually stressed and radially graded Mooney–Rivlin hollow circular cylinders to provide insights into how grading their material moduli according to a power law function of the radius can be advantageously used. We simulate residual stresses in a thin wall hollow cylinder by inverting it inside out and in a thick wall cylinder by assuming that a longitudinal wedge opening parallel to the cylinder axis is closed by deforming it axisymmetrically. It is found that positive integer values of the power law exponent are generally advantageous but its negative values can have deleterious effects on stress distributions. Furthermore, a hollow cylinder with residual stresses generated by one of the foregoing methods in the reference configuration should be modeled as orthotropic rather than transversely isotropic for subsequent deformations. The analytical solutions provided here should help numerical analysts verify their algorithms for large deformations of rubber-like materials that are modeled by the Mooney–Rivlin relation, and design engineers for exploiting the radial gradation of the two material moduli to reduce structure’s mass without sacrificing its performance.

  PublisherDOI

• First Failure Load of Rectangular Laminated and Sandwich Plates Using Isogeometric Analysis

  AIAA Journal · 2024-09-19

  article

  This paper investigates the first failure load of simply supported and clamped laminate and sandwich plates loaded by a distributed normal traction on the top surface. A third-order shear and normal deformable plate theory, the isogeometric basis functions, and five failure criteria, namely, the maximum stress, the Tsai–Wu, the Tsai–Hill, the Hoffman, and the Hashin for laminated plates, and only the Tsai–Hill criterion for sandwich plates are used in this study. Of these, Hashin’s criteria distinguish between the fiber and the matrix failure. The in-plane stresses are found from the plate displacements and Hooke’s law, and the transverse stresses are recovered by integrating the equilibrium equations through the thickness. Effects of the plate aspect ratio, the fiber angle, the face sheet materials, and the core materials on the first failure load are identified. The computed results are found to agree well with those reported in the literature. Whereas the five failure criteria for laminated plates predict nearly the same value of the first failure load, they do not provide the same location of the failure initiation.

  PublisherDOI

• Torsion and Extension of Functionally Graded Mooney–Rivlin Cylinders

  Journal of Elasticity · 2024-11-21 · 3 citations

  articleOpen accessSenior author

  Abstract We analytically study finite torsional and extensional deformations of rubberlike material circular cylinders with the two material moduli in the Mooney–Rivlin relation assumed to be continuous functions of the undeformed radius. It is shown that under null resultant axial load on the end faces the cylinder length increases upon twisting. Furthermore, when the two moduli are affine functions of the radius the inhomogeneity parameters can be found to have the maximum shear stress occur at a pre-determined interior point. Whereas the radial stress is finite at the center of a cross-section of a homogeneous material cylinder, it may have large values for an inhomogeneous material cylinder. The closed-form solutions provided herein for the two moduli having affine, power-law and exponential functions of the radius should benefit numerical analysts verify their algorithms and engineers design soft material robots for improving their performance under torsional loads.

  PublisherOA PDFDOI

• First failure load of rectangular laminated and sandwich plates using isogeometric analysis

  2024-01-04

  article

  We investigate the first failure load of simply-supported and clamped laminate and sandwich plates loaded by a distributed normal traction on the top surface. We use a third-order shear and normal deformable plate theory (TSNDT), the isogeometric basis functions, and five failure criteria, namely, the maximum stress, the Tsai-Wu, the Tsai-Hill, the Hoffman, and the Hashin for laminated plates and the Tsai-Hill criterion for the sandwich plates. Of these, only the Hashin criteria distinguish between the fiber and the matrix failure. The in-plane stresses are found from the plate displacements and Hooke’s law and the transverse stresses are recovered by integrating through the thickness equilibrium equations. Effects of the plate aspect ratio, the fiber angle, the face sheet materials, and the core materials on the first failure load are identified. The computed results are found to agree well with those reported in the literature.

  PublisherDOI

• Analytical solutions and material tailoring for combined radial expansion and twisting of functionally graded orthotropic hollow cylinders

  Thin-Walled Structures · 2024-06-12 · 2 citations

  articleSenior authorCorresponding
  PublisherDOI

• Discussion of the paper “M. Askari-sedeh and M. Baghani, On the extension-torsion of short hyperelastic tubes of axially functionally-graded materials” [Eng Struct 301 (2024) 117344]

  Engineering Structures · 2024-05-14

  article1st authorCorresponding
  PublisherDOI

• Thermal performance of fouling-resistant polymer nanocomposite coatings in heat exchangers

  International Journal of Heat and Mass Transfer · 2023-07-23 · 7 citations

  articleSenior author
  PublisherDOI

Frequent coauthors

• Davide Spinello

  University of Ottawa

  17 shared

• Guojun Nie

  Tongji University

  17 shared

• Senthil S. Vel

  17 shared

• Maurizio Porfiri

  17 shared

• Jiashi Yang

  15 shared

• David Dillard

  Virginia Tech

  15 shared

• Z.‐H. Jin

  15 shared

• Christopher B. Williams

  12 shared

Education

• PH.D., mechanical enigneering

  Johns Hopkins University

  1972