DOI: 10.5061/dryad.pk0p2ngw8
title: Experimental studies on snaking in 3D-printed cylindrical shells under axial compression using photogrammetry

description: The buckling instability of cylindrical shells under axial compression has
 been one of the most renowned problems in structural engineering for
 several decades. Many pioneering works in the 20th century have provided
 insights into understanding the shells' infamous imperfection
 sensitivity and led to reliability-based designs. However, a recent surge
 in numerical studies of the snaking phenomenon explores the development of
 a localised stable post-buckling mode in axially compressed cylindrical
 shells. Hitherto, none of the experimental studies report on the evolution
 of azimuthal snaking. In this work, experimental studies are carried out
 with the objective of revealing the snaking phenomenon. The axial
 compression experiments are performed on 3D-printed shells made of
 thermoplastic polyurethane (TPU). The work's novelty lies in the
 usage of TPU shells for slowing down the propagation of circumferential
 dimples and making it feasible to capture them using Photogrammetry.
 Despite the match between the experimental and numerical mode shapes, the
 experiments reveal multiple routes for the snaking sequence. Furthermore,
 mode transitions such as reduction in circumferential wave number and
 transformation of symmetric mode into an asymmetric one are observed.
 These experimental results provide insights into the localised phenomenon
 of snaking and validate numerical solutions.
description: The dataset of Numerical results of buckling of 3D printed shells
 was generated using ABAQUS, a Finite element software.
 The dataset of Experimental results of buckling of 3D printed
 shells consists of load-displacement response under compression. In
 addition, the post-buckling mode shapes of the shell acquired using
 Photogrammetry were also uploaded.
description: This README file was generated on 18/01/2024 by G Raju. GENERAL
 INFORMATION 1. Title of Dataset: Experimental studies on snaking in
 3D-printed cylindrical shells under axial compression using photogrammetry
 2. Author Information A. Principal Investigator Contact Information Name:
 G Raju Institution: Indian Institute of Technology, Hyderabad Address:
 India Email: B. Associate or
 Co-investigator Contact Information Name: V Ravulapalli Institution:
 Indian Institute of Technology, Hyderabad Address: India Email:
 3. Date of data collection:
 March-December 2023
 \#####################################################################
 SHARING/ACCESS INFORMATION 1. Recommended citation for this dataset: Raju,
 Gangadharan; Ravulapalli, Vineeth; Narayanamurthy, Vijayabaskar (2024).
 Experimental studies on snaking in 3D-printed cylindrical shells under
 axial compression using photogrammetry. Dryad Digital Repository.
 2. Links to other publicly
 accessible locations of the data: None
 \#####################################################################
 SUMMARY OF DATASET CONTENTS: Using the contents of the dataset the Finite
 element simulation results and the experimental buckling response of the
 shell can be reproduced.
 \#####################################################################
 DESCRIPTION OF THE DATA AND FILE STRUCUTRE The dataset consists of Zipped
 folders, which can be extracted using software like WinZip or WinRAR. 1.
 The folder "Photogrammetry_Route_A_Experiment_data" contains the
 MATLAB figures used to present the dimples' propagation in section
 4.2.2.1. (Route A) of the paper. Their corresponding point clouds are
 provided as '.xyz' files. The '.Zip' files contain the
 pictures required to obtain these point clouds using the procedure
 described in the paper. The Excel spreadsheet contains the axial
 load-displacement response acquired from a load cell. 2. The folder
 "Numerical study_data" contains the input file for generating
 the Odd Snaking results presented in section 2.2. The videos of all the
 presented finite element results are provided as '.avi' files.
 \#####################################################################
 DATA-SPECIFIC INFORMATION (A) Details of
 Photogrammetry_Route_A_Experiment_data.zip folder: The following files can
 be extracted by unzipping the folder: 1. Data type: MATLAB Figure File
 list: a. Route_A_1 b. Route_A_2 c. Route_A_3 d. Route_A_4 e. Route_A_5
 Description: The MATLAB software can access these figures and their
 contents. The figures can be used to reproduce the dimples'
 propagation results presented in section 4.2.2.1.(Route A) of the paper.
 2. Data type: '.xyz' File list: a. Route_A_1.xyz b.
 Route_A_2.xyz c. Route_A_3.xyz d. Route_A_4.xyz e. Route_A_5.xyz
 Description: The '.xyz' files consist of the point clouds
 acquired using Photogrammetry as described in the paper. These files can
 be read using software like NOTEPAD, Microsoft Word, Microsoft Excel, or
 equivalent tools. Each row of a '.xyz' file represents
 rectangular coordinates of a buckled shell's geometry, separated by
 blank spaces. These files can be used to generate the provided MATLAB
 figures. 3. Data type: WinZIP folders File list: a. Route_A_1_pics b.
 Route_A_2_pics c. Route_A_3_pics d. Route_A_4_pics e. Route_A_5_pics
 Description: Each Zipped folder contains the JPG format pictures required
 to obtain these point clouds using the procedure described in section
 4.1.2 of the paper. 4. Data type: Microsoft Excel Worksheet File Name:
 Route_A_load-disp Description: The Worksheet consists of the
 experimentally acquired axial load-displacement response of the shell,
 presented in Figure 9 of the paper. (B) Details of
 Numerical_study_data.zip folder: The following files can be extracted by
 unzipping the folder: 1. Data type: Input file ('.inp') File
 Name: Odd_snaking_input_file Description: By importing this input file
 into ABAQUS software, the buckling response of a single dimpled shell can
 be acquired, and the Odd Snaking results presented in section 2.2 can be
 reproduced. 2. Data type: '.avi' File list: a. Even_snaking b.
 Odd_snaking c. Measured_geom_Imperfection Description: These
 '.avi' video files animate the finite element results presented
 in the paper.
 \#####################################################################
 LIST OF REQUIRED SOFTWARE 1. MATLAB 2. Microsoft Excel 3.
 NOTEPAD/Microsoft Word 4. ABAQUS 5. Meshroom 6. Meshlab 7. Netfabb (for
 scaling the geometry)