Research

Our Mission

Our research focuses on mitigating the effects of natural hazards on the built environment through understanding of the behavior of existing structures and the development of new resilient systems incorporating novel response mechanisms and advanced materials. To achieve these objectives, our research lies at the nexus of performance-based engineering, computational structural mechanics and dynamics, and experimental methods for large-scale structures and materials.

A list of research grants is available here.

Research Areas

Our research focuses on the broad interconnected areas of Resilient and Sustainable Structures and Computational Structural Mechanics in the framework of novel materials and advanced construction methods.

Additive Construction (or Construction 3D Printing)

The focus of this area is on the development of methods from additive construction, and the integration of such methods with structural design and enviromental analyses to achieved resilienece and sustinability

Analysis, Design and Experimental Evaluation of 3D Printed Concrete Housing

This research pursues design methodologies for future adoption of 3D printed concrete housing within widely used design standards. This project builds upon ongoing work of Dr. Sideris on the analysis of 3D printed concrete structural components. This research is funded by the Department of Housing and Urban Development (HUD).

Current and Former Grad. Student Researchers: M. El Tahlawi (Texas A&M), M. Aghajani Delavar (Texas A&M), H. Chen (Texas A&M), S. Sharma (Texas A&M)

Hempcrete 3D Printed Housing

This research pursues the development of hempcrete 3D printed structures that will be resilient and net carbon negative for applications in residential and commercial construction. This research has been developing new materials, new printing methods and new structural designs.

Current and Former Grad. Student Researchers: D. Smith (Texas A&M.), Zoheb Faisal (Texas A&M), Xincheng Wang (Texas A&M), M. El Tahlawi (Texas A&M), S. Sharma (Texas A&M), M. Syed (Texas A&M)

Resilient and Sustainable Structures

The focus of this area is on the development, design, simulation and testing of resilient and sustainable structures. Resiliency against natural hazards is realized via novel response mechanisms and new materials. Sustainability is further explored through energy harvesting concepts

Bridges with Hybrid Sliding-Rocking (HSR) Columns for Accelerated Construction and Seismic Resilience

This research builds on early work by Dr. Sideris and is currently conducted in collaboration with Dr. A.B. Liel (University of Colorado at Boulder) through funding provided by the NSF (CMMI 1538585/1748031). HSR columns are precast concrete segmental columns incorporating internal unbonded post-tensioning, sliding joints distributed over the column height, and rocking joints at the column ends. Joint sliding is achieved by introducing a thin layer of silicone material at the interface of the sliding joints to achieve a targeted coefficient of friction. Compared with monolithic and post-tensioned rocking columns, HSR columns offer large deformation capacity without damage, via small sliding of multiple joints over the column height. Joint sliding also offers energy dissipation capabilities to control seismic displacement demands and helps to control peak forces and accelerations by partly acting as a multilevel seismic isolation system. Our research in this topic includes mechanics-based modeling of HSR columns, development of performance-based design methodologies for bridges with HSR columns, and large-scale experimentation. Recent prior work in this area has led to the development of a Capacity Spectrum Method for bridges with HSR columns.

Primary Grad. Student Researchers: M. Salehi (Texas A&M) and J. Valigura (CU-Boulder)

Bridges with Polyurethane-enhanced Columns for Seismic Resilience

This research aims at integrating polymeric materials in the design of bridge columns in order to eliminate concrete damage in plastic hinge locations. The proposed design integrates (1) polyurethane (PU) segments at the column ends to accommodate large rotations without damage, (2) external replaceable energy-dissipating (ED) links to provide supplemental hysteretic damping and flexural stiffness and strength, and (3) internal unbonded post-tensioning to provide self-centering. The ED links will be external and easily replaceable, allowing for rapid retrofit following high intensity earthquakes. Our research has focused on experimental characterization and constitutive modeling of selected PUs, seismic performance assessment of bridges with PU-enhanced columns, and large-scale testing on PU-enhanced columns. Partial support has been provided by BASF

Primary Grad. Student Researcher: M. Nikoukalam (Texas A&M)

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Aging Effects in Performance-Based Seismic Design and Assessment of Reinforced Concrete Structures

This research is funded by the National Institute of Standards and Technology (NIST) through NIST’s Disaster Resilience Research Grants Program (see recipients here) and is conducted in collaboration with Dr. M. Hubler (University of Colorado - Boulder). This research aims at integrating material aging effects within the context of performance-based seismic design methodologies and current seismic design codes. This research will include: experimental characterization and constitutive modeling of concrete accounting for aging, structural simulations and performance assessments of RC structures including aging effects, and large-scale testing of aged RC members.

Primary Grad. Student Researchers: Codi McKee (Texas A&M ) and Sannidhya Kumar Ghosh (CU-Boulder)

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Sustainable Structures via Energy Harvesting

This research aims at introducing energy harvesting in structural design as a means of enhancing overall system sustainability. The objective of this work is to explore designs that provide large-scale energy harvesting under service loads (e.g., wind loads) and vibration mitigation under extreme loads (e.g., earthquake loads) through the use of energy harvesting elements.

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Computational Mechanics - Elasticity, Damage, Softening and Structural Collapse

The focus of this research area is on the simulation of damage and softening of structural members in order to predict the response of structures under dynamic loads

Thermo-Chemo-Hygro-Mechanical Simulation of Cementitious Materials

This research focuses on describing the behavior of concrete from the fresh to the hardened state accounting for environmental conditions, such as humidity and temperature. It investigates viscoelasticity, plasticity and damage, and introduces new constitutive laws and new finite element formulations for implementation in physics-based finite element analysis software, such as Abaqus

Primary Researchers: Juan Sebastian Rincon Tabares (Texas A&M) & D. Sebastian Martinez (Texas A&M)

Variationally Consistent Higher Order Beam Mechanics via Polynomially Augmented Radial Basis Functions

This research explores higher order beam theores that enrich Navier’s kinematic hypothesis of plane sections with polynomially augmented (PA) radial basis functions (RBFs) as a means of predicting accurately nonlinear cross-section responses, such as Poisson’s effect, bending (with in-plane deformations), and torsional warping. The RBFs are interpolants that have strong stability properties and are capable of reproducing highly nonlinear fields. They also permit stable expansion that is achieved by including additional RBF centers/grid points, the distribution of which can be based on the shape of the cross-section. The polynomial augmentation ensures that a certain order of polynomial completeness is achieved to account for cross-sections and loading conditions that result in polynomial solutions for the displacement fields. Using this concept, variationally-consistent beam equilibrium equations have derived, and beam element formulations have been developed.

Primary Student Researcher: Ruturaj Chiddarwar (Texas A&M)

Chiddarwar_et_al_Beams_Torsion Slide.mp4

Gradient Inelastic Beam Theory and Flexibility-based Frame Element formulation

This research introduces a new gradient inelastic (GI) beam theory and develops a corresponding flexibility-based frame element formulation for the analysis of framed structures. The proposed theory is obtained by the introduction of gradient nonlocality relations between material (local) section strains and macroscopic section strains (from the strain-displacement equation). From an analytical perspective, the major advantage of this theory is that it allows use of any (local) material constitutive laws. From a computational perspective, its major advantage lies in the high convergence rate of the corresponding flexibility-based formulation. This formulation eliminates strain location and achieves response objectivity (i.e. convergence with mesh refinements). Furthermore, the proposed flexibility formulation results in a single elegant system of nonlinear algebraic equations which can be solved using simple iterative methods (e.g., Newton-Raphson iterations) avoiding the complicated nested loop solution formats, which are currently used in various applications. This formulation was recently extended to account for finite strains and rotations and member instabilities (buckling).

Primary Student Researcher: M. Salehi (Texas A&M)

Mesh Convegence of GI Formulation, after Sideris and Salehi (2016)

Constitutive Modeling of Glassy Polymers for Structural Applications

This research investigates and develops constitutive models for polymeric materials for structural applications. The models combine viscoelasticity with viscoplasticity and damage

Primary Student Researcher: M. Nikoukalam (Texas A&M)

Structural Damping for Nonlinear Structural Systems

This research addresses the deficiencies of the Rayleigh damping model in the case of inelastic systems, such as those experiencing yielding and hardening, and/or damage and softening, and/or systems with dominant friction mechanisms (e.g. Hybrid sliding-rocking columns).

Primary Student Researcher: M. Salehi (Texas A&M)

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Path-following Methods for Quasi-static Analysis of Softening Structure

Adopting the principles of the predictor-corrector numerical continuation methods, a new method, entitled “Generalized Normal Flow Method with Online Step Controls”, is developed to identify equilibrium paths of nonlinear structural systems exhibiting softening under quasi-static loading. The developed method provides online step-size control and improved performance against backward path-tracing.

System exhibiting snap-back response

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