In the last decades, long-term structural health monitoring of civil structures has been mainly performed using two approaches: model based and data based. The former approach tries to identify damage by relating prediction numerical (e.g., finite-element) models structure. latter is driven, where measured from a given state condition are compared baseline or reference condition. A challenge in both approaches make distinction between changes response caused environmental operational...

Classifiers based on machine learning algorithms trained through hybrid strategies have been proposed for structural health monitoring (SHM) of bridges. Hybrid use numerical and data together to improve the process algorithms. The models, such as finite-element (FE) are used augmentation assumption existence limited experimental sets. However, a model might fail in providing reliable data, its parameters not share same underlying operating conditions observed real situations. Meanwhile,...

The effects of operational and environmental variability have been posed as one the biggest challenges to transit structural health monitoring (SHM) from research practice. To deal with that, machine learning algorithms proposed learn experience based on a reference data set. These work well if conditions under which bridge operates do not change over time. Meanwhile, climate has concerns for bridges. Although uncertainty associated magnitude is large, fact that our changing unequivocal....

In structural health monitoring of bridges, machine learning algorithms for damage detection are typically trained using an unsupervised strategy, with data gathered from systems, and assuming the structures undamaged functioning under normal operational conditions during a certain period time. However, scarcity information regarding response seasonal environmental variations less frequent makes distinction between these states damaged ones very challenging may cause to yield false...

The broad availability and low cost of smartphones have justified their use for structural health monitoring (SHM) bridges. This paper presents a smartphone application called App4SHM, as customized SHM process damage detection. App4SHM interrogates the phone's internal accelerometer to measure accelerations, estimates natural frequencies, compares them with reference data set through machine learning algorithm properly trained detect in almost real time. is tested on sets from laboratory...

Bridges play a crucial role in modern societies, regardless of their culture, geographical location, or economic development. The safest, most economical, and resilient bridges are those that well managed maintained. Recently, climate change has been posed as one the greatest concerns for health bridges. Although uncertainty associated with magnitude is large, fact our changing unequivocal. As result, making to priority authorities. A well-planned early intervention may save lives money....

Bridges are built to last more than 100 years, spanning many human generations. Throughout their lifetime, service requirements may change, or they age and often suffer a material degradation process that can lead the need of retrofitting. In bridge engineering, retrofitting refers strengthening existing structures make them resistant increase lifespan bridges. Retrofitting normally increases stiffness components, which cause significant changes in global modal properties. context structural...

The success of detecting damage robustly relies on the availability long periods past data covering multiple weather scenarios and information contained in used during learning process. Thus, innovation this paper is to apply a hybrid set train Gaussian process regression, assuming practically plausible range environmental conditions. proposed model presents satisfactory performance detect when structural changes caused by are blurred with temperature. Rather than relying exclusively...

Abstract The equations that govern the dynamic response of saturated porous media are first discretized in time to define boundary value problem supports formulation hybrid‐Trefftz stress element. (total) and pore pressure fields directly approximated under condition locally satisfying domain conditions problem. solid displacement outward normal component seepage independently on Unbounded domains modelled using either unbounded elements satisfy Sommerfeld or absorbing enforce weak form. As...

The displacement model of the hybrid-Trefftz finite element is formulated for elastodynamic problems defined on unsaturated soils. mathematical formulation based theory mixtures with interfaces. considers full coupling between solid, fluid and gas phases, including effects relative (seepage) accelerations. hyperbolic problem integrated in time using a step-by-step implicit scheme that transforms it into series elliptic space. free-field solutions these are derived cylindrical coordinates...

SUMMARY The stress model of the hybrid‐Trefftz finite element is formulated for analysis elastodynamic problems defined on unsaturated porous media. supporting mathematical theory mixtures with interfaces and considers full coupling between solid, fluid gas phases, including effect seepage acceleration. Hybrid‐Trefftz elements use free‐field regular solutions homogeneous Navier (or Beltrami) equation to construct approximation generalized stresses in domain element. influence non‐homogeneous...

A new indirect approach to the problem of approximating particular solution non-homogeneous hyperbolic boundary value problems is presented. Unlike dual reciprocity method, which constructs approximate solutions using radial basis functions, polynomials or trigonometric method reported here uses homogeneous obtained by discarding all time-derivative terms from governing equation. Nevertheless, what typifies present a conceptual standpoint option not these trial functions exclusively for...

Summary A new dual reciprocity‐type approach to approximating the solution of non‐homogeneous hyperbolic boundary value problems is presented in this paper. Typical variants reciprocity method obtain approximate particular solutions two steps. In first step, source function approximated, typically using radial basis, trigonometric or polynomial functions. second obtained by analytically solving equation having approximation as term. However, trial functions way have complicated expressions...

With the continuous evolution of numerical methods and availability advanced constitutive models, it became a common practice to use complex physical geometrical nonlinear analyses estimate structural behavior reinforced concrete elements. Such simulations may yield complete time history behavior, from first moment load is applied until total collapse structure. However, cracking pattern in discontinuous zones elements associated failure modes are relatively phenomena their simulation...