Subhamoy Sen

Indian Institute of Technology Mandi | भारतीय प्रौद्योगिकी संस्थान मंडी · School of Civil and Environmental Engineering

Periodic health assessment of large civil engineering structures is an effective way to ensure safe performance all through their service lives. Dynamic response based structural health assessment can only be performed under normal/ambient operating conditions. Existing Kalman filter (KF) based parameter identification algorithms that consider para...

Kalman Filter (KF) based parameter estimation assumes Gaussianity of the system parameters and thus propagates only the first two moments of the states. Application of Particle filter or Ensemble Kalman filter to estimate non-Gaussian parameters, although more accurate, is computationally expensive. Generalized polynomial chaos (gPC) is well-known...

Structural health monitoring research traditionally focuses on detecting damage in members excluding the possibility of weakened joint conditions. Efficient model-based joint damage detection algorithms demand computationally expensive model that may affect the promptness of detection. Deep learning techniques have recently come up as an efficient...

Bayesian filtering based structural health monitoring algorithms typically assume stationary white Gaussian noise models to represent an unknown input forcing. However, typical structural damages occur mostly under the action of extreme loading conditions, like earthquake or high wind/waves, which are characteristically non-stationary and non-Gauss...

Fatigue estimation for critical structures necessitates comprehensive monitoring, which, in turn, requires dense instrumentation and models that heavily rely on computational resource. However, the fatigue vulnerability of different segments within the infrastructure can be considered to adopt a cost-effective substructure-based monitoring approach...

Monitoring linear time-varying (LTV) systems using model-based approaches typically requires dense instrumentation and high-fidelity support models, resulting in significant computational and financial costs. Bayesian filtering-based methods adopt a joint state-parameter estimation approach for LTV system monitoring wherein states/parameters are ob...

Meso-scale homogenization of elastic and thermo-elastic properties of concrete is carried out using a semi-random sequential adsorption algorithm taking basis on properties of aggregate randomly distributed in a homogenized matrix (cement mortar). The aggregates are generated by the sequential reduction of a cuboid into a polyhedron with multiple f...

Vehicle-induced vibration may cause fatigue in bridge structures leading to sudden failure causing loss of economy and human lives. Structural fatigue estimation is a complicated proposition since the entire structure needs to be monitored irrespective of the fatigue proneness of different parts. This eventually invites huge computational costs due...

Monitoring the health of large-scale infrastructure with the required precision necessitates high-dimensional support models and extensive instrumentation. However, in a model-based structural health monitoring (SHM) framework, the ability to localize damage is constrained by the discretization of the model. To enhance the resolution of discretizat...

This paper focuses on developing a water and energy-saving reliable irrigation system using state-of-the-art computing, communication, and optimal energy management framework. The framework integrates real-time soil moisture and weather forecasting information to decide the time of irrigation and quantity of water required for potato crops, which i...

Please cite this article as: , Toward improving water-energy-food nexus through dynamic energy management of solar powered automated irrigation system, HELIYON (2024), doi: https:// Abstract 15 This paper focuses on developing a water and energy-saving reliable irrigation system using 16 state-of-the-art computing, communication, and optimal energy...

Managing the early-age thermal behavior of mass concrete structures like dams, dykes, bridge piers, thick raft foundations, etc., is the major concern during their construction. The heat of hydration (HOH) of the fresh concrete pour does not get easily dissipated to ambiance since concrete is predominantly a poor conductor of heat. Eventually, in t...

Soil moisture (SM) plays a crucial role in agriculture planning, especially controlling irrigation and crop growth. While the application of physics-based models requires detailed information of the complex land-atmospheric interaction and high heterogeneity in soil characteristics, the machine learning-based modeling approaches have been proved to...

Engineering structures, including bridges, undergo fatigue loads over time, leading to material degradation, reduced resistance, and increased risk of failure. Regular local inspections or structural health monitoring (SHM) are crucial to identify potential failures and predict fatigue life. However, challenges arise in predicting the remaining use...

Composites are extensively used in various fields such as civil, aerospace, naval due to their high specific stiffness and strength. These properties are adversely affected due to damage. For damage detection, vibration-based methods are generally used which use modal parameters, i.e. modal frequencies, mode shapes and modal damping ratios. These m...

Structural Health Monitoring (SHM) enables assessing in-service structures' performance by localizing structural anomaly instances immediately after their occurrence. Typical SHM approaches monitor the entire structural spatial domain aggravating the required density and cost of instrumentation. Further, with model-based approaches, the entire stru...

Typically, for linear parameter varying systems, which can potentially get influenced by spatiotemporal external parameters, possible changes in their eigen structure are not easy to be attributed conclusively to system faults or spatiotemporal parametric variations. Such spatiotemporal variations can although be estimated alongside, yet at the cos...

A standardized experiment for validating Structural Health Monitoring (SHM) methods is taken up. The test structure is a laboratory-scale five-storey steel frame designed with joints that can be easily detached or reattached as needed. The relatively heavier joints mimic the real-life rigid structural joints fabricated with extensive use of gusset...

Bridge health monitoring has been attempted to ensure the safety of the bridges in their operations, employing various measurement options like acceleration, strain, displacement, etc. The relative efficacy of these measurements as a damage-sensitive response has remained a topic of research. While acceleration has traditionally been used in abunda...

Bridges play a crucial role in transportation across water bodies, junctions, etc., minimizing the distance and traffic in a route. With ageing and continuous use, the bridges deteriorate and may even collapse if not monitored. With the gradual deterioration of its health, the dynamic properties alter with time. This damage-sensitive feature is the...

Typical machine learning (ML)-based structural health monitoring (SHM) techniques rarely take ambient variation in temperature and its subsequent effect on structural stiffness into consideration, while their impacts on the structural response are substantial. Moreover, typical modal or time-domain SHM approaches can delay the detection procedure e...

In steel structural systems, joints failures (yielding, cracking and loosening of bolts and brackets) are more frequent compared to member failure due to the design philosophy that allows joints to be weaker than members in order to avoid significant casualty in case of extreme loading situations. Yet, joint damage assessment has not been explored...

Structural health monitoring(SHM) techniques rarely consider the effect of ambient temperature, even though its impact on the structures being substantial. Moreover, typical modal or time-domain SHM approaches may delay the detection of damages endangering human lives due to their requirement of response time histories of sufficient length. Targeti...

Tensegrities are structural mechanisms, with dedicated compression (struts/bars) and tension members (cables). The compression members float inside the network of tension members. Tensegrities are characterized by the presence of at least one infinitesimal mechanism, which is stabilized by the pre-stress present in the members, to ensure the equili...

Accurate forecasting of soil moisture (SM) is crucial for managing the irrigation demands effectively. The dynamics of SM is largely controlled by interaction between land and atmosphere. As an alternate to physics based models, the machine learning based tools have been shown to yield better accuracy in forecasting SM. However, the complexity in t...

The trend of high speed travel is continuing to spread around the world. Whilst Japan and several European nations are now trying to extend or improve their high-speed railway networks, Asian countries such as India, Thailand, Indonesia, Singapore, and Malaysia are entering the design, construction and field-testing stages of their high-speed rail...

Tensegrity is a network of bars and cables that maintains its structural integrity with tension present in its cables. Other than typical structural failure mechanisms, tensegrity may fail due to slacking of cables or buckling of bars. Real-life tensegrities are an assemblage of component modules. Large tensegrities require excessive computation fo...

To avert catastrophic failure in the structures, joints are typically designed to yield, but not fail, so that energy accumulated under cyclic loading is dissipated. Eventually, this renders the structural joints to be characteristically weaker and more vulnerable than the members. Yet, damage detection research mostly assumes damage in the members...

Bayesian filtering based approaches for diagnosis of structural damage have been widely employed in structural health monitoring (SHM) research. The approach however may lead to an inaccurate alarm/decision due to the presence of faulty sensor/s. Nevertheless, sensor faults are inevitable during real field SHM in which sensor may malfunction or get...

Bayesian filtering-based Structural Health Monitoring (SHM) approaches predominantly employed Extended and Unscented Kalman filter variants (EKF and UKF) for joint estimation of states and parameters. In these approaches, a set of parameters denoting location-based system health indices are either appended in the response state vector of the system...

Traditional approaches for structural health monitoring (SHM) seldom take ambient uncertainty (temperature, humidity, ambient vibration) into consideration, while their impacts on structural responses are substantial, leading to a possibility of raising false alarms. A few predictors model-based approaches deal with these uncertainties through comp...

Tensegrities form a special case of truss, wherein compression members (struts/bars) float within a network of tension members (cables). Tensegrities are characterized by the presence of at least one infinitesimal mechanism stabilized with member pre-stress to ensure equilibrium. Over prolonged usage, the cables may lose their pre-stress while the...

Typical civil infrastructures are prone to fatigue-induced failure due to repeated loading during their service life. To effectively manage the consequences of fatigue-induced failure, the remaining useful life (RUL) of a structure must be estimated on the basis of a certain established parameterized fatigue model. Eventually estimation of the pert...

Sensor types and their positioning is a major factor in structural health monitoring (SHM) to ensure certainty in estimation. While acceleration has predominantly been employed for damage detection, they are known to be costly and not frame invariant (except for moderately accurate GPS based accelerometers). A thorough monitoring of a real life str...

The dynamic properties of bridges can be affected not only through damage but also from ambient uncertainty. False-positive or negative alarms may be raised if environmental effects are not considered in the detection algorithm. This article presents a two-step data-driven approach that can incorporate temperature effects in vibration-based damage...

Tensegrity structures form a special class of truss with dedicated cables and bars, that take tension and compression, respectively. To ensure equilibrium, the tensegrity members are required to be prestressed. Over prolonged usage, the cables may lose their prestress while bars may buckle, affecting the structural stiffness as well as its dynamic...

The dynamic characteristics of any structural system get affected not only due to damage but also from variations in ambient uncertainty. Thus, false positive or negative alarm may be signalled if temperature effects are not taken care off. The difficulty lies in correlating response measurements to corresponding damage patterns in the presence of...

The use of the nonstationary hydrological frequency analysis (HFA) has been prompted when nonstationarity is diagnosed in hydrometeorological data. However, the inconclusive identification of the physical process(es) and driver(s) behind the nonstationarity challenges the identification of an appropriate model structure, and consequently might hind...

The unique nature and stability criterion for tensegrity structures demand a special approach for their design. Form finding is the method that identifies a stable shape for a tensegrity by optimizing the coordinate positions of its free nodes. The ultimate outcome for form-finding is the level of prestress (in terms of force densities) for which t...

Recent changes in climate, anthropogenic activities and land-use patterns have significantly altered the hydrological cycle and thus led to the presence of non-stationarity in hydrological data series. Existing conventional approaches for hydrological frequency analysis (HFA) have commonly overlooked non-stationarity and consequently they might pro...

Tensegrity structures can be defined as structural mechanisms having separate tension and compression members, where compression members are discontinuous and float in a network of tension members. Before incorporating tensegrity into major construction works, stability and safety of tensegrity as a structure has to be studied and scrutinized prope...

The dynamic characteristics of any structural system get affected not only due to damage but also from variations in ambient uncertainty. Thus, false positive or negative alarm may be signalled if temperature effects are not taken care off. The difficulty lies in correlating response measurements to corresponding damage patterns in the presence of...

Structural modal property gets affected not only due to damage but also variation inambient temperature, humidity etc. Detection of damage through modal comparison thus may lead to false predictions. This article presents a two-stage data-driven approach in which damage detection and localization are performed in consequence. For detection, an auto...

Existing filtering based structural health monitoring (SHM) algorithms assume constant noise environment which does not always conform to the reality as noise is hardly stationary. Thus to ensure optimal solution even with non-stationary noise processes, the assumed statistical noise models have to be updated periodically. This work incorporates a...

Existing filtering based structural health monitoring (SHM) algorithms assume constant noise environment which does not always conform to the reality as noise is hardly stationary. Thus to ensure optimal solution even with non-stationary noise processes, the assumed statistical noise models have to be updated periodically. This work incorporates a...

Modal property of structural system gets affected not only due to the presence of damage but also due to a variation of environmental agents like temperature, humidity etc. Detection of damage through modal parameter comparison thus may lead to false predictions. This article presents a two-stage data-driven approach in which damage detection and l...

Standard filtering techniques for structural parameter estimation assume that the input force is either known or can be replicated using a known white Gaussian model. Unfortunately for structures subjected to seismic excitation, the input time history is unknown and also no previously known representative model is available. This invalidates the af...

Standard filtering techniques for structural parameter estimation assume that the input force either is known exactly or can be replicated using a known white Gaussian model. Unfortunately for structures subjected to seismic excitation, the input time history is unknown and also no previously known representative model is available. This invalidate...

Buckling strength (P_n) of cold-formed steel (CFS) members depends not only on their non-dimensional slenderness λ_c , but also on the geometric imperfection (d) inherently present due to their cross-sectional slenderness. Previous works on strength characterization of CFS members although provide estimate for P_n as a function of nondimensional sl...

Although Kalman filter (KF) was originally proposed for system control i.e. steering a system as desired by monitoring the system states, its application for parameter estimation problems is widespread because of the excellent similarity between these two apparently different problem types in state space description. In standard Kalman filter, syst...

Existing Kalman filter-based parameter identification algorithms estimate the system parameters as either sole states or a subset of augmented states. While the former approach requires the measurement to be sufficiently clean, the latter is reported to have numerical stability issues. Since the parameters are estimated in both these approaches in...

In this article, a novel approach to damage identification (location as well as intensity) is presented using eigenstructure assignment (ESA)-based finite-element model (FEM) updating. ESA is a control-based approach that utilises state or output feedback of a system to alter its eigenstructure. The proposed method identifies the system’s state tra...

A novel control theory-based eigenstructure assignment (ESA) technique is employed to update the finite element model (FEM) of a linear time-invariant system. The proposed method uses state feedback to produce the gain matrix which in turn updates the existing system matrices through simultaneous assignment of eigenvalue-vector pairs in the FEM gen...

Exactness of the Bouc-Wen hysteresis model entirely depends on the correctness of the model parameters. This paper applies Extended and Unscented Kalman filtering approach with adaptive process and measurement error covariance matrix to identify these parameters in an efficient way. We define time invariant model parameters as states of the process...

Eigenstructure assignment (ESA) based model updating is a control based technique for systematic calibration of finite element models using measured response from real structure. Application of this technique in physical space restricts simultaneous updating of stiffness and damping matrices of any mechanical system. On the other hand ESA when used...

Modern day structural health monitoring involves prediction of structural health for possible future load cases for which structure may behave nonlinearly and thus rendering its simplistic linear predictor model obsolete. Among the existing nonlinear material models Bouc-Wen hysteresis model drew most of the attention in recent past due to its wide...

Mathematical models deviate from real structures owing to assumptions regarding boundary conditions, model order selection, material and geometric parameters and numerical errors, all of which may lead to incorrect prediction of structural response. The objective of model updating is therefore to adjust the mathematical model so that it can predict...

A simple mixed variational formulation for the higher order zig-zag shear deformable coupled magneto-electro-elastic plates with a continuous interlaminar shear-stress is presented in this paper. Starting from a generalized kinematics (i.e., mechanical displacement, electric and magnetic potentials) defined for a generic layer, the simplified lamin...