Dynamic buckling of imperfection-sensitive structures

Small geometrical imperfections in some structures can be responsible for large reductions in their static buckling strengths. As is well known, a thin shell is often very imperfection-sensitive in this sense, with a perfect specimen sometimes having a "classical" buckling strength several times higher than that of an imperfect one. Many analytical studies have sought to correlate reductions in buckling strength with assumed initial imperfections of various sizes and shapes. Such studies may eventually provide the quantitative information needed for the establishment of a statistical theory of buckling, which would relate the probability of buckling under a given static load to the spectrum of imperfections (see [1]). But at the present time, the design of shells leans heavily on experiment, and analysis has been mainly useful in identifying imperfection-sensitive structures and in establishing, in a qualitative way, the degree of this sensitivity.