Summary
Buckling of stochastically imperfect finite columns on a mixed quadratic-cubic elastic foundation is studied. The imperfection function is assumed to be a normally distributed random function of the space coordinate with given mean function and autocorrelation function. The problem is solved by the Monte-Carlo-Method. The Fourier coefficients of the initial imperfection function, expanded in terms of the buckling modes of the associated perfect column, are simulated. For each trial the buckling load is obtained numerically, and the results are used in constructing the reliability function at a specified load (defined as the probability of the buckling load exceeding this specified load). The study is a sequel to an earlier work of the author concerning the reliability of stochastically imperfect columns on a purely cubic nonlinear elastic foundation.
Similar content being viewed by others
Abbreviations
- A :
-
positive constant, Eq. (67)
- A pqrm :
-
defined in Eq. (22)
- a :
-
arbitrary constant, Eq. (3)
- B :
-
positive constant, Eq. (67)
- B pqm :
-
defined in Eq. (21)
- B(p+q, m) :
-
defined in Eq. (21)
- c mk :
-
elements ofC
- c ijmp :
-
defined in Eq. (44)
- d :
-
end-shortening of column
- d k :
-
standard independent normal variables
- E :
-
Young's modulus
- e imp :
-
defined in Eq. (44)
- erf (...):
-
error function
- E[v(η)]:
-
mean function
- \(F(u,\bar u)\) :
-
functional of nondimensional displacements
- I :
-
section moment of inertia
- I m :
-
defined in Eq. (20)
- I m (N) :
-
defined in Eq. (38)
- J m :
-
defined in Eq. (20)
- J m (N) :
-
defined in Eq. (38)
- \(K_{\bar u} (\eta _1 ,\eta _2 )\) :
-
nondimensional autocovariance function
- \(K_{\bar v} (\eta _1 ,\eta _2 )\) :
-
nondimensional autocovariance function
- k 1,k 2,k 3 :
-
elastic foundation constants
- l :
-
length of column
- M :
-
number of trials
- m :
-
number of half-waves
- m * :
-
number of half-waves at buckling
- N :
-
number of terms taken into account
- n :
-
subscript
- P :
-
axial load
- P E :
-
buckling load of column without foundation
- P cl :
-
buckling load of column on linear foundation
- R :
-
required reliability
- R(α′):
-
reliability at load level α′
- \(\bar U\) :
-
mean imperfection function
- u :
-
nondimensional additional displacement
- \(\bar u\) :
-
nondimensional initial imperfection
- \(\bar v\) :
-
initial imperfection before cutting
- w :
-
additional deflection
- \(\bar w\) :
-
initial imperfection
- x :
-
axial coordinate
- α:
-
nondimensional load
- αm :
-
defined in Eq. (23)
- α* :
-
buckling load, load-carrying capacity
- γ(ϰ1):
-
defined in Eq. (13)
- δij :
-
Kronecker delta
- Δ:
-
radius of gyration
- ϰ1, ϰ2, ϰ3 :
-
elastic foundation constants
- η:
-
nondimensional axial coordinate
- ξk,\(\bar \xi _k\) :
-
Fourier coefficients
- \(\langle \bar \xi _k \rangle\) :
-
mean value of\(\bar \xi _k\)
- \(\bar \xi _{m(1,2)}\) :
-
defined in Eq. (57)
- μM :
-
number of α* values exceeding α′
- σmn :
-
elements of variance-covariance matrix
- 〈...〉:
-
mathematical expectation
References
Elishakoff, I.: Buckling of a stochastically-imperfect finite column on a nonlinear elastic foundation — a reliability study. J. Appl. Mech.46, 411–416 (1979).
Reissner, E.: On postbuckling behavior and imperfection sensitivity of thin plates on a non-linear elastic foundation. Studies Appl. Math. XLIX, No. 1, 45–47 (1970).
Reissner, E.: A note on imperfection sensitivity of thin plates on a non-linear elastic foundation. In: Instability of continuous systems (Leipholz, H. H. E., ed.), Proceedings of IUTAM Symposium held at Herrenalb, September 1969, pp. 15–18, Berlin-Heidelberg-New York: Springer 1971.
Keener, J. P.: Buckling imperfection sensitivity of columns and spherical caps. Quat. Appl. Math.32, 173–199 (1974).
Fraser, W. B., Budiansky, B.: The buckling of a column with random initial deflections. J. Appl. Mech.36, 232–240 (1969).
Hansen, J. S., Roorda, J.: On probabilistic stability theory for imperfection sensitive structures. Int. Jour. Solids and Structures10, 341–359 (1974).
Hansen, J. S., Roorda, J.: Reliability of imperfection sensitive structures. In: Stochastic problems in mechanics (Ariaratnam, S. T., Leipholz, H. H. E., eds.), Proceedings of the Symposium on Stochastic Problems in Mechanics, held at the University of Waterloo, September 1973, pp. 229–242.
Fraser, W. B.: Buckling of a structure with random imperfections. Ph. D. Thesis, Division of Engineering and Applied Physics, Harvard University, Cambridge, Mass., May 1965.
Fraser, W. B.: Private communication, September 1978.
Timoshenko, S. P., Gere, J. M.: Theory of elastic stability, 2nd ed., pp. 94–98. New York: McGraw-Hill 1961.
Elishakoff, I.: Remarks on the static and dynamic imperfection—sensitivity of nonsymmetric structures. J. Appl. Mech.47, 111–115 (1980).
Budiansky, B., Hutchinson, J.: Dynamic buckling of imperfection—sensitive structures. In: Proceedings of the Eleventh International Congress of Applied Mechanics, Munich 1964 (Goertler, H., ed.) pp. 636–651.
Qiria, V. S.: Motion of the bodies in resisting media. Proceedings of the Tbilisi State University44, 1–20 (1951) (In Russian.)
Davidenko, D. F.: On one new method of numerical solution of the systems of non-linear equations. Doklady Akademii Nauk SSSR. Proceedings of the Academy of Sciences of USSR88, No. 4, 601–602 (1953) (In Russian.)
Shreider, Ya. A. (ed.): Method of statistical testing: Monte Carlo Method. (Translation from Russian.) Amsterdam: Elsevier 1964.
Hammersley, J. M., Handscomb, D. G.: Monte Carlo Methods. London: Methuen 1964.
Elishakoff, I.: Simulation of space-random fields for solution of stochastic boundary value problems. J. Acoust. Soc. Amer.65, 399–403 (1979).
Elishakoff, I.: Impact buckling of thin bar via Monte Carlo Method. J. Appl. Mech.45, 586–590 (1978).
Elishakoff, I.: Probabilistic methods in the theory of structures, pp. 433–468. New York: J. Wiley 1983.
Elishakoff, I.: Hoff's problem in a probabilistic setting. J. Appl. Mech.47, 403–408 (1980).
Massey, F. J., jr.: The Kolmogorov-Smirnov test for goodness of fit. J. Amer. Statist. Ass.46, 253, 68–78 (1951).
Elishakoff, I., Arbocz, J.: Reliability of axially compressed cylindrical shells with random axisymmetric imperfections. Int. J. Solids and Structures18, 563–585 (1982).
Elishakoff, I., Arbocz, J.: Stochastic buckling of shells with general imperfections. In: Stability in the mechanics of continua, (Schroeder, F. M., ed.), pp. 306–317. Berlin-Heidelberg-New York: Springer 1982.
Koiter, W. T.: On the stability of elastic equilibrium, Ph. D. Thesis, Delft University of Technology. Amsterdam: H. J. Paris. (In Dutch). English Translation: (a) NASA TTF-10, 833, 1967, (b) AFFDL-TR-20, 1970 (translated by Riks, E.).
Budiansky, B., Hutchinson, J. W.: Buckling: Progress and challange. In: Trends in solid mechanics, (Besseling, J. F., Van der Heijden, A. M. A., eds.), Proceedings of the Symposium Dedicated to the 65th Birthday of W. T. Koiter, pp. 93–116. Sijthoff and Noordhoff 1979.
Arbocz, J., Babcock, C. D., jr.: Prediction of buckling loads based on experimentally measured initial imperfections. In: Buckling of structures, (Budiansky, B., ed.), pp. 291–311. Berlin-Heidelberg-New York: Springer 1976.
Elishakoff, I.: How to introduce initial-imperfection sensitivity concept into design. In: Collapse: The buckling of structures in theory and practice, (Thompson, J. M. T., Hunt, G. W., eds.), Proceedings of the I.U.T.A.M. Symposium, University College London, 1982, pp. 345–357.
Author information
Authors and Affiliations
Additional information
Dedicated to Prof. Dr. Ir. Warner Tjardus Koiter on the occasion of his 70th birthday.
With 7 Figures
Rights and permissions
About this article
Cite this article
Elishakoff, I. Reliability approach to the random imperfection sensitivity of columns. Acta Mechanica 55, 151–170 (1985). https://doi.org/10.1007/BF01267987
Received:
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF01267987