Buckling of Steel Plates Under Rotational Restraints: An Integration of Experimental Testing and the Vibration Correlation Technique

Background

Plates are essential structural elements in many practical applications and commonly undergo buckling failures because of compressive types of loadings. An accurate prediction of buckling loads without destructing the plate has always been an important factor for researchers and designers.

Objective

This study investigates the buckling load of axially compressed plates under rotational restraints through a combined approach of experimental testing and the vibration correlation technique (VCT).

Methods

The experimental setup contains equipment to apply elastic rotational restraints to simulate practical structural conditions. Buckling of the plates with diverse length-to-width ratios (a/b) and the stiffness of rotational restraint K were examined through a specially designed fixture. Additionally, mode shapes through the buckling tests were extracted and the influence of rotational restraints on the post-buckling behavior was discussed.

Results

It is noted that the elastic boundary conditions significantly affected the post-buckling behavior, resulting in notable variations in the load-carrying capacity of the plates. An exponential relationship between the load-carrying capacity and the a/b ratios, exhibiting a systematic decrease as a/b increased from 1.5 to 3. The effect of K on limit loads showed a maximum change of 6% within the scope of the study and it goes to 2% at a/b = 3. However, K is observed to have a significant impact on the post-buckling behavior and the load-carrying capacity in the post-buckling region is almost maintained at higher K values.

Conclusion

The influence of rotational restraints on the prediction capability of the VCT approach is highlighted. Probabilistic error distribution analysis indicates an average error of 12%, with a 99% confidence interval. The outcomes of this investigation contribute to the refinement of predictive models and methodologies for evaluating buckling loads under realistic conditions.