Database of Uniaxial Cyclic and Tensile Coupon Tests for Structural Metallic Materials

Database of Uniaxial Cyclic and Tensile Coupon Tests for Structural Metallic Materials

Background

This dataset contains data from monotonic and cyclic loading experiments on structural metallic materials. The materials are primarily structural steels and one iron-based shape memory alloy is also included. Summary files are included that provide an overview of the database and data from the individual experiments is also included.

The files included in the database are outlined below and the format of the files is briefly described. Additional information regarding the formatting can be found through the post-processing library (https://github.com/ahartloper/rlmtp/tree/master/protocols).

Usage

The data is licensed through the Creative Commons Attribution 4.0 International.

If you have used our data and are publishing your work, we ask that you please reference both:

this database through its DOI, and

any publication that is associated with the experiments. See the Overall_Summary and Database_References files for the associated publication references.

Included Files

Overall_Summary_2022-08-25_v1-0-0.csv: summarises the specimen information for all experiments in the database.

Summarized_Mechanical_Props_Campaign_2022-08-25_v1-0-0.csv: summarises the average initial yield stress and average initial elastic modulus per campaign.

Unreduced_Data-#_v1-0-0.zip: contain the original (not downsampled) data

Where # is one of: 1, 2, 3, 4, 5, 6. The unreduced data is broken into separate archives because of upload limitations to Zenodo. Together they provide all the experimental data.

We recommend you un-zip all the folders and place them in one "Unreduced_Data" directory similar to the "Clean_Data"

The experimental data is provided through .csv files for each test that contain the processed data. The experiments are organised by experimental campaign and named by load protocol and specimen. A .pdf file accompanies each test showing the stress-strain graph.

There is a "db_tag_clean_data_map.csv" file that is used to map the database summary with the unreduced data.

The computed yield stresses and elastic moduli are stored in the "yield_stress" directory.

Clean_Data_v1-0-0.zip: contains all the downsampled data

The experimental data is provided through .csv files for each test that contain the processed data. The experiments are organised by experimental campaign and named by load protocol and specimen. A .pdf file accompanies each test showing the stress-strain graph.

There is a "db_tag_clean_data_map.csv" file that is used to map the database summary with the clean data.

The computed yield stresses and elastic moduli are stored in the "yield_stress" directory.

Database_References_v1-0-0.bib

Contains a bibtex reference for many of the experiments in the database. Corresponds to the "citekey" entry in the summary files. 

File Format: Downsampled Data

These are the "LP__Specimen__processed_data.csv" files in the "Clean_Data" directory. The is the load protocol designation and the is the specimen number for that load protocol and material source. Each file contains the following columns:

The header of the first column is empty: the first column corresponds to the index of the sample point in the original (unreduced) data

Time[s]: time in seconds since the start of the test

e_true: true strain

Sigma_true: true stress in MPa

(optional) Temperature[C]: the surface temperature in degC

These data files can be easily loaded using the pandas library in Python through:

import pandas
data = pandas.read_csv(data_file, index_col=0)

The data is formatted so it can be used directly in RESSPyLab (https://github.com/AlbanoCastroSousa/RESSPyLab). Note that the column names "e_true" and "Sigma_true" were kept for backwards compatibility reasons with RESSPyLab.

File Format: Unreduced Data

These are the "LP__Specimen__processed_data.csv" files in the "Unreduced_Data" directory. The is the load protocol designation and the is the specimen number for that load protocol and material source. Each file contains the following columns:

The first column is the index of each data point

S/No: sample number recorded by the DAQ

System Date: Date and time of sample

Time[s]: time in seconds since the start of the test

C_1_Force[kN]: load cell force

C_1_Déform1[mm]: extensometer displacement

C_1_Déplacement[mm]: cross-head displacement

Eng_Stress[MPa]: engineering stress

Eng_Strain[]: engineering strain

e_true: true strain

Sigma_true: true stress in MPa

(optional) Temperature[C]: specimen surface temperature in degC

The data can be loaded and used similarly to the downsampled data.

File Format: Overall_Summary

The overall summary file provides data on all the test specimens in the database. The columns include:

hidden_index: internal reference ID

grade: material grade

spec: specifications for the material

source: base material for the test specimen

id: internal name for the specimen

lp: load protocol

size: type of specimen (M8, M12, M20)

gage_length__mm_: unreduced section length in mm

avg_reduced_dia__mm_: average measured diameter for the reduced section in mm

avg_fractured_dia_top__mm_: average measured diameter of the top fracture surface in mm

avg_fractured_dia_bot__mm_: average measured diameter of the bottom fracture surface in mm

fy_n__mpa_: nominal yield stress

fu_n__mpa_: nominal ultimate stress

t_a__deg_c_: ambient temperature in degC

date: date of test

investigator: person(s) who conducted the test

location: laboratory where test was conducted

machine: setup used to conduct test

pid_force_k_p, pid_force_t_i, pid_force_t_d: PID parameters for force control

pid_disp_k_p, pid_disp_t_i, pid_disp_t_d: PID parameters for displacement control

pid_extenso_k_p, pid_extenso_t_i, pid_extenso_t_d: PID parameters for extensometer control

citekey: reference corresponding to the Database_References.bib file

yield_stress__mpa_: computed yield stress in MPa

elastic_modulus__mpa_: computed elastic modulus in MPa

fracture_strain: computed average true strain across the fracture surface

c,si,mn,p,s,n,cu,mo,ni,cr,v,nb,ti,al,b,zr,sn,ca,h,fe: chemical compositions in units of %mass

file: file name of corresponding clean (downsampled) stress-strain data

File Format: Summarized_Mechanical_Props_Campaign

Meant to be loaded in Python as a pandas DataFrame with multi-indexing, e.g.,

tab1 = pd.read_csv('Summarized_Mechanical_Props_Campaign_' + date + version + '.csv',
index_col=[0, 1, 2, 3], skipinitialspace=True, header=[0, 1],
keep_default_na=False, na_values='')

citekey: reference in "Campaign_References.bib".

Grade: material grade.

Spec.: specifications (e.g., J2+N).

Yield Stress [MPa]: initial yield stress in MPa

size, count, mean, coefvar: number of experiments in campaign, number of experiments in mean, mean value for campaign, coefficient of variation for campaign

Elastic Modulus [MPa]: initial elastic modulus in MPa

size, count, mean, coefvar: number of experiments in campaign, number of experiments in mean, mean value for campaign, coefficient of variation for campaign

Caveats

The files in the following directories were tested before the protocol was established. Therefore, only the true stress-strain is available for each:

A500

A992_Gr50

BCP325

BCR295

HYP400

S460NL

S690QL/25mm

S355J2_Plates/S355J2_N_25mm and S355J2_N_50mm