Dynamic scaling laws of spatial grid structures under inner explosion considering material and geometric distortions

Abstract

It is a key issue to assure that the experimental results of scaled-down models of long-span spatial grid structure under inner blasting loads can truly reflect the characteristics of their prototype structure. The existing method to deal with the dynamic scaling laws of structures is not suitable for long-span spatial grid structures subjected to inner explosion. This paper derives and modifies the dynamic scaling laws among scaled-down models and full-size structure under inner explosion on the basis of dimensional analysis, taking long-span cylindrical grid shell structure as research case and considering the strain-rate effect, yield stress and dimension distortions. In this article, the improved scaling laws were verified and proved by comparing the simulation results with the test results of long-span cylindrical grid shell structure and its scaled-down models. The research results revealed that the maximum errors of the peak values of displacement responses and strain responses between the scaled-down model and the prototype were unacceptable without considering material and geometric distortions. Moreover, the empirical formulae to calculate the mass of explosive based on specific impulse were proposed and the corrected method to predict the inner explosion responses of full-size structure according to the results of scaled-down model tests was presented.

Keywords:

• Dynamic
• similarity law
• inner explosion
• spatial grid structure
• strain-rate effect
• geometric distortion

Acknowledgements

The authors are very grateful to the National Natural Science Foundation of China (Grant no. 51278208), the Key projects of science and technology plan of Fujian Provincial Department of Science and Technology (Grant no. 2018Y0063), and the Subsidized Project for Postgraduates’ Innovative Fund in Scientific Research of Huaqiao University (Grant no. 17011086003) for the financial support of this work.

Data availability

The raw/processed data required to reproduce these findings cannot be shared at this time as the data also forms part of an ongoing study.

Declaration of interests

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

CRediT author statement

Gao Xuanneng: Conceptualization; Funding acquisition; Methodology; Project administration; Resources; Supervision; Validation; Writing—review & editing. Fu Shiqi: Data curation; Formal analysis; Investigation; Validation; Writing—original draft. Liu Qian: Data curation-Supporting; Writing—typing checking & proofreading. Chen Daohe: Data curation-Supporting; Investigation-Supporting; Resources-Supporting; Validation-Supporting. Zheng Qi: Project administration-Supporting; Resources-Supporting; Validation-Supporting. Chen Xin: Data curation-Supporting; Formal analysis-Supporting; Investigation; Validation-Supporting. Wang Wenbao: Project administration-Supporting; Validation-Supporting.