Data processing: measuring – calibrating – or testing – Measurement system in a specific environment – Mechanical measurement system
Reexamination Certificate
1999-07-12
2003-04-22
Hoff, Marc S. (Department: 2857)
Data processing: measuring, calibrating, or testing
Measurement system in a specific environment
Mechanical measurement system
C702S041000, C073S788000, C073S851000, C073S796000
Reexamination Certificate
active
06553320
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to a method for testing the stability of vertically anchored masts in which the mast above its anchoring is loaded with an increasing bending force proceeding from a defined initial value until at the most a maximum, predetermined test force and at the same time is laterally deflected and in which the mast after completion of the loading procedure is again unloaded and with this is subjected to a restoring force reducing to zero.
In EP0 638 794 A1 there is described a method for testing the solidity and bending resistance of a vertically anchored mast with which the mast likewise is subjected to a variable bending moment in that it is loaded with a force introduced above its anchoring and increasing in the course of the testing procedure, the measured value and the course of the force being used to determine the solidity of the mast. The mentioned force as well as also the distance about which the mast is laterally deflected at a selected location on account of the bending moment are measured simultaneously with sensors.
A linear dependency of the measured distance on the introduced force is evaluated as information of a mast deflection lying in the region of elastic deformation, whilst the determining of a non-linear dependency of the values measured by the sensors are evaluated as information of a plastic deformation and/or for a non-stable anchoring of the mast which is then recognized as not having bending resistance or is not stable and the testing procedure is stopped by unloading the mast. Thus with this method no safety precautions are to be made for the case that is not to be exected, specifically that the mast with this testing step may buckle or break. Moreover the testing procedure is only broken off by unloading the mast when a predetermined nominal value of the bending moment is achieved in the elastic region of deformation, which means that the mast is sufficiently stable and has bending resistance and does not need to be exchanged for another.
In accordance with one embodiment, the following results and information were achieved:
RESULT:
INFORMATION:
A) S2 > 0, S4 > 0
no tilting shifting, but a
loading characteristic curve course equal,
plastification of the mast in
whose end force values are approximately
both testing procedures.
equal;
b) S2 > 0, S4 = 0; S2 = 0, S4 > 0
no tilting shifting but a
loading characteristic curve course
fracture lengthened on
unequal, essentially a straight lined
testing.
reaching of FPmax in a testing procedure;
c) S2 > 0, S4 > 0
no tilting shifting, but
loading characteristic curve course
tension fracture corrosion
essentially equal, however, end force
or intercrystalline corrosion
values in the second testing procedure
in the mast.
higher;
d) S2 = S4
only tilting shifting in first
as a whole an unequal loading
testing procedure.
characteristic curve course second loading
characteristic curve beginning very flat and
steeply rising at 54 until Fpmax;
e) S2 < S4
tilting shifting in the first
as a whole an unequal loading
testing procedure, fracture
characteristic curve course, second loading
recognition with the second
characteristic curve beginning very flat and
testing procedure.
steeply rising at S4;
f) S2 > S3
tilting shifting and
as a whole an unequal loading
plastification of the mast
characteristic curve course, second loading
with the first testing
characteristic curve beginning very flatly
procedure.
and at S3 increasing heavily, testing forces
equal with both testing procedures;
With this method it is not possible to determine whether the mast tested in each case, in spite of deformation lying in the elastic region until reaching the testing load, is damaged by a fracture or by a corrosion region possibly going through the mast, so that in the case of such damage one may possibly arrive at an erroneous evaluation of the remaining stability of the mast, since for example with the application of this method a linear course of the function S=f(F), wherein F is the introduced force and S the lateral deflection of the mast, or a changing bending angle of the mast may give the delusion that the mast is not damaged.
This problem is solved by the method described in the Utility Model DE 296 07 045 U in which by way of a force unit the mast above its anchoring in the same plane of testing is loaded from the side, after one another with a compression force and with a tensile force, thus with oppositely directed bending moments so that for both cases of loading there results two functions f
x
and f
y
and these can be processed in an evaluation unit and compared. Furthermore these functions are usefully displayed on a monitor and/or graphically represented with a printer for the simultaneous assessment or subsequent evaluation.
These functions with an assumed straight course particularly give much information inasmuch as they give information whether there is damage caused for example by a fracture in the mast and where this damage is located.
If both functions f
x
, f
y
have the same course and thus the same gradient, it may be concluded that in any case no damage of the mast in the vertical testing plane and in the mast region directly next to this plane will be present. If on the other hand the courses of the two functions f
x
, f
y
related to the same zero point diverge and thus have differing gradients then a mast damage may be concluded even when the characteristic curves obtained from the two functions run linearly or straight, since a mast for example damaged with a fracture even after a further development of the fracture with an increasing loading of the mast will continue to behave elastically and a fracture formation at the most would result in a small kink in the otherwise continued linearly running characteristic curve.
As has already been mentioned, from the two functions obtained in the same testing plane and from their courses also the location of the damage may be concluded. If specifically e.g. the function f
x
evaluated with the compression procedure has a larger gradient than the function f
y
determined with the tensile procedure, this would mean that the fracture is located on the side of the mast on which the tensile force is indroduced, since it is to be expected that the mast on account of the smaller spreading of a transversly running fracture, without this at the same time having to become larger, will behave more elastically than with a compression force introduced in the opposite direction with which oppositely lying fracture surfaces are pressed together and the mast with this loading direction will behave less elastically as one without a fracture formation.
All previously dealt with methods have the common disadvantage that with them the condition that the mast or its anchoring with the respective loading cases may change its position in or on the ground may not be exactly taken into account. In any case it may happen that with the testing procedures it may for example arise that movements and a tilting shifting of the mast or its anchoring may occur on or in the ground and at the same time ground material is permanently displaced by the tilting of the mast or its anchoring, which of course would have an such effect on the course of the functions f that these would no longer give clear information on the stability of the mast as such.
BRIEF SUMMARY OF THE INVENTION
In particular this disadvantage is to be alleviated by the invention in that a method and a testing device are put forward with which in a relatively simple and above all secure manner a sound decision and answer to the question can be achieved as to whether on the one hand a tested mast is adequately stable and whether on the other hand the obtained measuring results may point to whether a shifting of the mast or its anchoring in the ground is present, wherein even on ascertaining such shifting, information is to be made possible whether the mast is damaged or not.
From one aspect, the invention relates to a method for testing the sta
Roch Mathias
Roch Oliver
Hoff Marc S.
Jacox Meckstroth & Jenkins
Kim Paul
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