EXPERIMENTAL ANALYSIS OF STRUCTURES


GENERAL DESCRIPTION OF THE COURSE

  • learning about the crucial methods for measuring of mechanical and physical quantities caused by static and dynamic loadings of structures,
  • learning about basic identification methods of structures and about the necessary instruments,
  • the introduction to a systematic approach to investigation of constructions

 

COURSE CONTENTS:

 

  • general concepts concerning investigations of structures (the purpose of the investigation, specimens, loadings, surveying and physical measurements and observations)
  • geodetic methods of displacement measurements (instruments, methods and compensations of the measured values, presentation of results, calculating the most probable value)

– Base of deformation analysis of geodetic nets for the purpose of adjusting geodetic measurements results

– Hanover method in the process of deformation analysis of geodetic nets

– Preparation of matrix weights

– Gauss-Marks model in deformation analysis of geodetic measurements,

– Geodetic networks for special purposes (construction of large bridges objects, object of smaller spans, …)

– Calculation of the impact on the measurement results

– Optimization of geodetic networks 2nd, 3th and 4th order

– Use of surveying instruments for measuring static and dynamic response of structures

– Surveying and Mapping tracking movements in all stages pollution

– Geodetic monitoring (preparation of geodetic equipment, measurement plan of surveying …)

 

  • electronic measurement of mechanical and other quantities (basis, accuracy and measurement uncertainty, configurations of the measuring equipment and software for data acquisition, measurement of strains, displacements, accelerations, inclinations, forces, torsion moments, hydraulic pressure, rotational speed, non-contact transmission of the measuring signals on rotating parts of structures, temperature, automation of measurements)
  • use of calibration methods for indirectly measuring the displacements, forces and moments through the strain measurements
  • processing, analysis and display of measurement results (filtering of measurement signals, analysis of disturbances and their causes, identification of the characteristics of the observed structures on the basis of measured quantities – determination of stiffness, natural frequencies, damping, assessing the remaining lifetime of the structure based on the results of measurements …)
  • implementation of measurements on structures (the purpose of measurement, the problem of reference points for measuring displacements, determination of the number, position and the accessibility of measurement points, triggering and control of measurements, standards and regulations), examples of good practice
  • monitoring of structures in various stages of construction and diagnostic methods for faults and defects of structures on the basis of measurement results.

 

Contents of exercises:

  • familiarization with measurement equipment, demonstration and implementation of individual measurements of displacements, strains, temperature, torque, forces, speed of rotation on simple structures in the lab)
  • static and dynamic bending test of a beam (surveying and electronic measurements of displacements, strains, load size, processing of measurement signals, evaluation and presentation of measurement signals and comparison with the calculated response)
  • demonstration and individual preparation of the measuring point for strain measurement on aluminum or steel cantilever bending element, implementation of the indirect force measurement with so prepared element after previous calibration
  • The load test on real simple bridge structure is implemented, where measurements of strains, vertical displacements and accelerations are performed; measured results are evaluated and graphically presented. A comparative static and dynamic analysis of the observed object is performed by the FE method using a suitable software tool, the computational and measurement results are compared and the causes of differences between the two are analyzed,
  • Redundant geodetic measurements of the beam for determination of vertical displacements of characteristics points on those beams using the state of the art geodetic equipment in more epochs

– Precise leveling of beam for determination of vertical displacements

 

STUDY MATERIALS:

 

  • Boersch & al.: Measurement Data Acquisition – Electrical measurement of mechanical and physical quantities, Süddeutscher Verlag onpact GmbH, 81677 Munich, 2012.
  • Tomaževič: Uvod v eksperimentalno analizo gradbenih konstrukcij, Univerza v Ljubljani, Ljubljana, 1991.
  • Hoffmann: An Introduction to Measurements using Strain Gages, Hottinger Baldwin Messtechnik, Darmstadt,1989
  • Hoffmann: Practical Hints for the Installation of Strain Gages, Hottinger Baldwin Messtechnik, Darmstadt, 4th revised edition,1996
  • Smernice Standardi (JUS, ASTM, DIN, SIST), ki obravnavajo preiskave gradbenih konstrukcij,
  • Kapović, Geodezija v niskogradnji, Sveučičište u Zagrebu, Geodetski fakultet, 2010
  • Vukotić: Ispitivanje konstrukcija, Gradjevinski fakultet Beograd, Naučna knjiga, Beograd, 1989.
  • Kovačič B., kamnik R., Praktična geodezija, učbenik, FG, Maribor, 2009