Vibration transmission across fractured beam-to-column junctions of reinforced concrete

2021 ◽  
Vol 263 (2) ◽  
pp. 4779-4786
Author(s):  
Marios Filippoupolitis ◽  
Carl Hopkins

To detect human survivors trapped in buildings after earthquakes by using structure-borne sound it is necessary to have knowledge of vibration transmission in collapsed and fragmented reinforced-concrete buildings. In this paper, Statistical Energy Analysis (SEA) is used to model the vibration transmission in seismic damaged reinforced concrete beam-to-column junctions where the connection between the beam and the column is made only via the steel reinforcement. An ensemble of 30 randomly damaged beam-to-column junctions was generated using a Monte Carlo simulation with FEM. Experimental SEA (ESEA) is then considered with two or three subsystems to determine the CLFs between the beam and the column with either bending modes or the combination of all mode types. It is shown that bending modes dominate the dynamic response and that the uncertainty of predicting the CLFs using FEM with ESEA is sufficiently low that it should be feasible to estimate the coupling even when the exact angle between the beam and the column is unknown. In addition, the use of two rather than three subsystems for the junction significantly decreases the number of negative coupling loss factors with ESEA.

CORROSION ◽  
1988 ◽  
Vol 44 (10) ◽  
pp. 761-765 ◽  
Author(s):  
S. Feliu ◽  
J. A. Gonzalez ◽  
C. Andrade ◽  
V. Feliu

2020 ◽  
Author(s):  
Pavlina Mateckova ◽  
Zuzana Marcalikova ◽  
David Bujdoš ◽  
Marie Kozielova

Author(s):  
Soffian Noor Mat Saliah ◽  
Noorsuhada Md Nor ◽  
Noorhazlinda Abd Rahman ◽  
Shahrum Abdullah ◽  
Mohd Subri Tahir

Author(s):  
Diego L. Castañeda-Saldarriaga ◽  
Joham Alvarez-Montoya ◽  
Vladimir Martínez-Tejada ◽  
Julián Sierra-Pérez

AbstractSelf-sensing concrete materials, also known as smart concretes, are emerging as a promising technological development for the construction industry, where novel materials with the capability of providing information about the structural integrity while operating as a structural material are required. Despite progress in the field, there are issues related to the integration of these composites in full-scale structural members that need to be addressed before broad practical implementations. This article reports the manufacturing and multipurpose experimental characterization of a cement-based matrix (CBM) composite with carbon nanotube (CNT) inclusions and its integration inside a representative structural member. Methodologies based on current–voltage (I–V) curves, direct current (DC), and biphasic direct current (BDC) were used to study and characterize the electric resistance of the CNT/CBM composite. Their self-sensing behavior was studied using a compression test, while electric resistance measures were taken. To evaluate the damage detection capability, a CNT/CBM parallelepiped was embedded into a reinforced-concrete beam (RC beam) and tested under three-point bending. Principal finding includes the validation of the material’s piezoresistivity behavior and its suitability to be used as strain sensor. Also, test results showed that manufactured composites exhibit an Ohmic response. The embedded CNT/CBM material exhibited a dominant linear proportionality between electrical resistance values, load magnitude, and strain changes into the RC beam. Finally, a change in the global stiffness (associated with a damage occurrence on the beam) was successfully self-sensed using the manufactured sensor by means of the variation in the electrical resistance. These results demonstrate the potential of CNT/CBM composites to be used in real-world structural health monitoring (SHM) applications for damage detection by identifying changes in stiffness of the monitored structural member.


2003 ◽  
Vol 6 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Sayed A. Attaalla ◽  
Mehran Agbabian

The characteristics of the shear deformation inside the beam-column joint core of reinforced concrete frame structures subjected to seismic loading are discussed in this paper. The paper presents the formulation of an analytical model based on experimental observations. The model is intended to predict the expansions of beam-column joint core in the horizontal and vertical directions. The model describes the strain compatibility inside the joint in an average sense. Its predictions are verified utilizing experimental measurements obtained from tests conducted on beam-column connections. The model is found to adequately predict the components of shear deformation in the joint core and satisfactorily estimates the average strains in the joint hoops up to bond failure. The model may be considered as a simple, yet, important step towards analytical understanding of the sophisticated shear mechanism inside the joint and may be implemented in a controlled-deformation design technique of the joint.


Sign in / Sign up

Export Citation Format

Share Document