skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Frequency domain observations of small motions at concrete/steel interfaces

Abstract

When two rough interfaces in contact are driven in harmonic motion, the frictional resistance to shear causes the response of the driven system to be nonlinear. Displacement along the interface cannot be described by a linear predictor, one analogous to Hooke`s law for elastic response. Laboratory experiments are described here to illustrate that the resulting motion is not random, but produces measurable and characteristic output at harmonics of the driving frequency. Although the geometry of the tests is not practical for evaluating the integrity of steel/concrete interfaces in structures, the results illustrate that the principle should apply to other geometries where shearing forces can be applied to interfaces to determine the quality of bonding.

Authors:
Publication Date:
Research Org.:
Lawrence Livermore National Lab., CA (United States)
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
274200
Report Number(s):
UCRL-ID-124224
ON: DE96013820
DOE Contract Number:
W-7405-ENG-48
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: Jun 1996
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING NOT INCLUDED IN OTHER CATEGORIES; MECHANICAL STRUCTURES; NONDESTRUCTIVE TESTING; MATERIALS TESTING; BONDING; INTERFACES; SHEAR; STEELS; CONCRETES; OSCILLATORS; MECHANICAL VIBRATIONS; TORSION

Citation Formats

Bonner, B.P.. Frequency domain observations of small motions at concrete/steel interfaces. United States: N. p., 1996. Web. doi:10.2172/274200.
Copy to clipboard
Bonner, B.P.. Frequency domain observations of small motions at concrete/steel interfaces. United States. doi:10.2172/274200.
Copy to clipboard
Bonner, B.P.. Sat . "Frequency domain observations of small motions at concrete/steel interfaces". United States. doi:10.2172/274200. https://www.osti.gov/servlets/purl/274200.
Copy to clipboard
@article{osti_274200,
title = {Frequency domain observations of small motions at concrete/steel interfaces},
author = {Bonner, B.P.},
abstractNote = {When two rough interfaces in contact are driven in harmonic motion, the frictional resistance to shear causes the response of the driven system to be nonlinear. Displacement along the interface cannot be described by a linear predictor, one analogous to Hooke`s law for elastic response. Laboratory experiments are described here to illustrate that the resulting motion is not random, but produces measurable and characteristic output at harmonics of the driving frequency. Although the geometry of the tests is not practical for evaluating the integrity of steel/concrete interfaces in structures, the results illustrate that the principle should apply to other geometries where shearing forces can be applied to interfaces to determine the quality of bonding.},
doi = {10.2172/274200},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sat Jun 01 00:00:00 EDT 1996},
month = {Sat Jun 01 00:00:00 EDT 1996}
}
Copy to clipboard
Technical Report:
View Technical Report (0.56 MB)
DOI:  10.2172/274200
Save / Share:
Export Metadata
Save to My Library
You must Sign In or Create an Account in order to save documents to your library.

  • ; ;
    When major electric power systems are interconnected through ties of relatively small capacity, low frequency intersystem oscillations are likely to be troublesome for some operating conditions. Spontaneous intersytem oscillations which have occurred in the western and some midwestern states attest to this aspect of system behavior. The long distances which separate concentrations of generating capacity in those systems also separate many individual generating plants from other machines, so that localized poorly damped higher frequency modes of oscillation also exist. The potential for unstable oscillations must be considered in planning the bulk generation and transmission system, in designing control systems formore » turbine-generators and dc line terminals, and in system operations. Present practice depends almost entirely on time domain simulation for large system analysis, with computing costs that are relatively high and information in a form which is often not well suited to study purposes. The objective of this research is to develop an alternative to time domain simulation for damping studies. This alternative involves the use of a linearized system model and the calculation of only those system natural frequencies of oscillation and damping factors that are most intimately related to generator rotor motions.« less

  • ; ;
    Mathematical models and computing methods for determining the natural freqencies and damping of generator rotor oscillations in large electric power systems are described. These models and methods provide the basis for estimating those eigenvalues most intimately related to rotor motion. The principal computational problem is the calculation of incremental voltage oscillations in a linear system model subjected to an external forcing function. This linear system model is derived from networks and generator representations employed in conventional time domain stability calculations. Methods of calculating voltages using this model are discussed. The use of these voltages in an iterative process to estimatemore » eigenvalues is explained.« less

  • ;
    This research was based on a two-part basic research investigation studying the effects of cement paste-aggregate interfaces (or interfacial transition zones-ITZ) on strength and durability of concrete. Part 1 dealt with the theoretical study and Part 2 dealt with the experimental.

  • ; ;
    Penetration assemblies are the parts required to be provided in the walls/domes of the concrete reactor containment structures to permit piping, mechanical devices, equipments, electrical cables, personnel movements etc. Integrity of arrangements with respect to leak tightness at and around these penetration assemblies, is of utmost importance for achieving safe functioning of containment. Although, the containment structures should ideally be designed for no-leakage condition but in practice this is not achievable. In view of this, one of the functional requirements of a containment is to restrict these leakages to an acceptable limit. If the leakages go beyond these limits formore » a containment, the containment may be considered to have failed in terms of leakage requirements, although structural failure in terms of strength and stability may not have occured. Considering the feasibilities in controlling leakages along different possible paths, it has been found necessary to study in detail the phenomenon of leakage through concrete-steel interfaces at and around containment penetration assemblies. 6 refs., 4 figs.« less