scholarly journals Shape-Sensing of Beam Elements Undergoing Material Nonlinearities

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 528
Author(s):  
Pierclaudio Savino ◽  
Marco Gherlone ◽  
Francesco Tondolo ◽  
Rita Greco

The use of in situ strain measurements to reconstruct the deformed shape of structures is a key technology for real-time monitoring. A particularly promising, versatile and computationally efficient method is the inverse finite element method (iFEM), which can be used to reconstruct the displacement field of beam elements, plate and shell structures from some discrete strain measurements. The iFEM does not require the knowledge of the material properties. Nevertheless, it has always been applied to structures with linear material constitutive behavior. In the present work, advances are proposed to use the method also for concrete structures in civil engineering field such as bridges normally characterized by material nonlinearities due to the behavior of both steel and concrete. The effectiveness of iFEM, for simply supported reinforced concrete beam and continuous beams with load conditions that determine the yielding of reinforcing steel, is studied. In order to assess the influence on displacements and strains reconstructions, different measurement stations and mesh configurations are considered. Hybrid procedures employing iFEM analysis supported by bending moment-curvature relationship are proposed in case of lack of input data in plastic zones. The reliability of the results obtained is tested and commented on to highlight the effectiveness of the approach.

2021 ◽  
Vol 14 (3) ◽  
pp. 36-44
Author(s):  
S. Nikolenko ◽  
Svetlana Sazonova ◽  
Viktor Asminin

A study of the properties of dispersed-reinforced concrete and a study of the effect of dispersed reinforcement on the operation of structures was carried out, mainly with a static load of the same sign. Based on the results of experimental studies, a comparison was made of the work of dispersed-laminated structures under alternating dynamic action of high intensity with the work of reinforced concrete beam elements under similar influences. The results of experimental studies of cubes and prisms for static and dynamic compression are also presented. The results of experimental studies allow us to conclude that there is a significant effect of dispersed reinforcement on the operation of structures under the investigated influences and the feasibility of combined reinforcement of structures. The use of dispersed reinforcement in structures will increase the resistance of structures to such influences.


2004 ◽  
Author(s):  
Gary A. Miller ◽  
Charles G. Askins ◽  
E. Joseph Friebele

2010 ◽  
Vol 47 (2) ◽  
pp. 180-196 ◽  
Author(s):  
Wei Dong Guo ◽  
H. Y. Qin

An experimental apparatus was developed to investigate the behaviour of vertically loaded free-head piles in sand undergoing lateral soil movement (wf). A large number of tests have been conducted to date. Presented here are 14 typical model pile tests concerning two diameters, two vertical pile loading levels, and varying sliding depths with the movement wf driven by a triangular loading block. Results are provided for driving force as well as for induced shear force (T), bending moment (M), and deflection ( y) along the piles with wf / normalized sliding depth. The tests enable simple expressions to be proposed, drawn from the theory for a laterally loaded pile. The new expressions well capture the evolution of M, T, and y with soil movement observed in current model tests, and the three to five times difference in maximum bending moment (Mmax) from the two modes of loading. They further offer a good estimate of Mmax for eight in situ pile tests and one centrifuge test pile. The study quantifies the sliding resistance offered by a pile for the given wf profiles, pile location (relative to the boundary), and vertical load. It establishes the linear correlation between the maximum thrust (resistance T) and Mmax, regardless of the magnitudes of wf.


2016 ◽  
Vol 844 ◽  
pp. 89-96 ◽  
Author(s):  
Peter Koteš ◽  
Josef Vican ◽  
Martina Ivašková

The evaluation of existing bridge structures is the most important process in the global Bridge Management System (BMS) because of providing the basic information about existing bridges required from the viewpoint of decision making process related to the optimal bridge maintenance and rehabilitation strategy. The theoretical approach using conditional probability and the positive effect of the inspection was developed. The new information concerning the actual structure condition is used in this mathematical model. This information is not available in the process of the new structure design [1]. The work is focused on structures subjected to bending [2]. The reinforced concrete beam elements with or without degradation were investigated. The corrosion of reinforcement bars was used as material degradation. The biggest effect of the inspection was obtained for members, which do not degrade. Hereby, the negative effect of degradation on reliability index is also demonstrated.


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