3 The main objective of this paper is to introduce a recently com piled cold-formed steel framed shear wall test database, 4 to reveal the database structure, and to present the method to access and present data. Many monotonic and cyclic 5 tests have been conducted on cold-formed steel framed shear wal ls in the last 20 years. Cold-formed steel framed 6 shear wall provisions in AISI S240, AISI S400, and ASCE 41 are supported by these tests. Recently the database has 7 been standardized and expanded to include additional tests, com plete cyclic information from tests, limit states, and 8 code prediction information. The database structure incorporate s ordered plain text files for each individual test; 9 c u s t o m M A T L A B c o d e s , w h i c h c a n r e a d , p r o c e s s , a n d p l o t d e s i g n a t ed database subsets; and a central Excel 10 spreadsheet that includes most descriptive information. The dat abase structure and basic in formation are summarized 11 herein and are aimed to advance the understanding and modeling of cold-formed steel framed shear walls . 12 1 Graduate Research Assistant, Department of Civil and Systems En gineering, Johns Hopkins Uni versity, Baltimore, MD 21218, USA, zhidongzhang@jhu.edu. 2 Graduate Research Assistant, Department of Civil and Systems En gineering, Johns Hopkins Uni versity, Baltimore, MD 21218, USA, eladly@jhu.edu. 3 Professor, Department of Civil Engineering, McGill University, Montreal, QC, Canada, colin.rogers@mcgill.ca. 4 Professor, Department of Civil and Systems Engineering, Johns H opkins University, Ba ltimore, MD 21218, USA, schafer@jhu.edu. 2 KEYWORDS 13 Earthquake engineering, Cold-form ed Steel, Shear walls, Test in formation, Test Strength, Database 14 3 INTRODUCTION 15 Various systems contribute to the lateral resistance of buildin gs framed from cold-formed steel (CFS). The overall 16 behavior, design, and performance of cold-formed steel lateral force-resisting systems ar e summarized in Madsen et 17 al. 2016. Predicting the lateral response of CFS-framed shear w alls can be complex as con siderable nonlinearity may 18 be generated at connections, in any sheathing materials, or in the framing steel itself. As a result, experimental testing 19 has taken a central role in studying the behavior of cold-forme d steel framed lateral force-resisting systems, as well 20 as providing strength and drift guidance for these systems. 21 Design provisions for lateral force resisting systems in the No rth American Standard for CFS Structural Framing (AISI 22 S240-20), the North American Sta ndard for Seismic Design of CFS Structural Systems (AISI S400-20), and the 23 Seismic Evaluation and Retrofit of Existing Buildings standard (ASCE41-17, ASCE, 2017) are constructed based on 24 available CFS-framed shear wall te st data. Therefore, the integ ration of tested cold-formed steel framed shear walls 25 into a comprehensive database is expected to provide a necessar y means for improving the understanding and design 26 of cold-formed steel framed systems. 27 Currently, 700 individual tests drawn from 29 different primary sources (Al-Kharat and Rogers, 2005; Al-Kharat and 28 Rogers, 2006; Balh and Rogers, 2010; Blais, 2006; Boudreault, 2 005; Branston, 2004; Briere and Rogers, 2018; Chen, 29 2004; Comeau, 2008; DaBreo, 2012; Elhajj, 2005; Hikita, 2006; K ochkine and Hill, 2006; Liu et al., 2012; Lu, 2015; 30 Morello, 2009; Morgan et al., 2002; Nguyen et al., 1996; Ong-To ne, 2009; Rizk and Rogers, 2018; Rokas, 2006; 31 Salenikovich AJ and Dolan JD, 1999; Santos and Rogers, 2018; Se rrette et al., 1997; UCI, 2004; Velchev, 2008; Yu 32 and Chen, 2009; Yu et al., 2007; Yu et al., 2007) are incorpora ted into the CFS framed shear wall test database 33 introduced herein. These collected tests include all CFS framed shear wall testing that underpins AISI S240-20 and 34 AISI S400-20. An initial version of this database supported the recent revision to ASCE41-17 (ASCE, 2017) for cold- 35 formed steel framing (Ayhan et al. 2016; Ayhan et al. 2018). Se ismic overstrength and seismic fragility function 36 research efforts were also conducted based on the database (Sch afer et al. 2020; Haghpanah and Schafer 2020). It is 37 worth noting that recent testing exploring higher capacity stee l sheet sheathed shear walls providing up to 145939 38 N/m (10,000 lbf/ft) capacity at McGill University (Santos and R ogers, 2018; Briere and Rogers, 2018; Rizk and 39 Rogers, 2018) have been incorporated into the database. 40 4 DATABASE STRUCTURE AND DETAIL 41 The database has a specific folder structure, a central Excel s preadsheet database, and an analysis engine driven by 42 custom MATLAB (R2018b) codes. There are three subfolders within the database home folder, including “Data”, 43 “Reference”, and “Analysis”. The “ Data” subfolder contains seve n folders named with affiliations where the shear 44 wall tests were conducted. Within every affiliation folder, the re is a “main” folder containing a series of ordered plain 45 text files, each corresponding to a shear wall test data. A “R eference” subfolder under the h ome folder stores source 46 literature (mainly test reports and degree theses) correspondin g to each test data group. An other “Analysis” subfolder 47 accommodates all the custom MATLA B codes and generates figure f iles after running the codes. 48 In the central database Excel spreadsheet, the fields are desig ned to capture all salient features of shear wall test 49 specimens and results that can be read into and utilized by cus tom MATLAB codes. Some of the key field information 50 are listed in Table 1, while the detailed database field dictio nary corresponding to the central database Excel 51 spreadsheet is summarized in the Appendix. English customary un its have been adopted within the database. The 52 paths of the raw test data text files are also stored inside th e central Excel spreadsheet, which can be accessed by the 53 custom MATLAB codes to read the exact raw plain text test data files. The link informati on between a certain source 54 and its corresponding reference is saved in a separate sheet wi thin the central Excel spr eadsheet. It is worth noting 55 that the Excel spreadsheet is intended as input to the analysis engine. Parameters selected f rom the test data response, 56 such as the peak strength, are h andled in the analysis engine b ut not stored in the spreadsheet. This is an intentional 57 decision to require the analys t to utilize the data files, not just the input spreadsheet. 58 59 60 61 62 63 64 65 66 5 Table 1. Data fields for the CFS-framed shear wall database 67 Information t ype Field cate gory Selected parameters within the fiel d Overall shear wall test information Basic identification id, source, test _no, loadin g_detail Wall overall loadin g,w i d t h ,h e i ght, thickness, Desi gnation1, sides Openin g details openin g_id, sheathin g area ratio, window _num, window _dim Tested shear wall configuration Strap bracin g details strap _detail, strap _width, strap _thickness, strap _grade Sheathin g details she_details, she _thickness, she _stren gth, she _spacin g_perimete r Chord stud details chord _web, chord _flange, chord _lip, chord _t, chord _nom_Fy Field stud details field_web, field _flange, field _lip, field _t, field _nom_Fy Track details track _web, track _flange, track _t, track _nom_Fy, track _actual _Fu Fastener stud trac k fastener _stud_track _no, fastener _stud_track _len Gusset plate details gusset _id, gusset _width, gusset _t, gusset _nom_Fy Bridging details bridging_loc, brid ging_web, bridging_flange, brid ging_t Hold down details holddown _id, holddown _no, holddown _offse t Ledger details ledger_id Strength and limit states Limit state est_primar y_failure, listed _failure _mode, notes _on_failure AISI S400-15 prediction S400 _USA _applicable, S400 _CAN _applicable, S400 _vn_USA Data files Data files data_units, data _dir, data _main, data _raw_txt, data _raw_image Processed data files proc_dxf, proc _cyclic, proc _mono, proc _backb, proc _backb _ave 6 The analysis engine is composed of a few custom MATLAB scripts reading in both the central spreadsheet and raw 68 text test data files following the accurate file path for deepe r manipulation of the data. These custom scripts are able 69 to process test data, visualize specific test or designated dat abase subset results, and further explore the database. The 70 four largest groups of tested sh ear walls can be classified by sheathing type. The force-def ormation response of all the 71 shear wall tests with wood struct ural panels, steel sheet sheat hing, strap bracing, and gypsum sheathing are presented 72 in Fig. 1, which presents an overview of the available data and overall hysteretic shape of CFS framed shear wall test 73 with different sheathing types. 74 75 Figure 1. Normalized drift vs. strength for all data in the shear wall d atabase. 76 DATABASE USAGE SAMPLE CODE AND OUTPUTS 77 There are three sample codes available in the CFS framed shear wall dataset. The first sample code deals with the 78 situation where we would like to find a specific test, plot the test force-deformation curv e, and obtain the peak force 79 and corresponding drift ratio when we already know the unique t e s t I D ( w h i c h c a n b e f o u n d i n t h e s u m m a r y 80 spreadsheet). 81 7 The second sample code addresses the situation in which we need to find all the tests whose configuration match each 82 cell in the strength tables for CFS framed shear walls sheathed with Wood Structural Panel (WSP) or Steel Sheet (SS) 83 in AISI S400-20, further plotting these force-deformation curve s and obtaining the average peak force and 84 corresponding aver age drift ratio. 85 It is important to note that many of the tests in the shear wal l database are not compliant with detailing requirements 86 in the design specifications – it is up to the analyst to ensur e that the selected data is appr opriate for their analysis – 87 the analysis code and spreadsheet provide necessary information to make this determination, and a field exists in the 88 spreadsheet as to whether or not the test is judged to be compl iant with AISI S400-15. The third sample code is able 89 to help us filter out all the tests with a particular type of s heathing, load protocol (monotonic or cyclic), and valid 90 detailing per AISI S400-20 as well as to plot the force-deforma tion curves and generate various histogram plots of 91 peak forces or peak force per unit wall width. 92 In the first sample code, “Datab ase_Usage_Example1.m”, there ar e three input parameters including “ID_Input”, 93 “write_switch”, and “units_output”. The “ID_Input” should be a unique test ID from the firs t column of the database 94 center spreadsheet, while the parameter “write_switch” determin es whether the code outputs the force and drift ratio 95 values and generates the force-deformation curve. If we set the “ID_Input” as 682 and the “write_switch” as 1, then 96 it is expected that the MATLAB command window outputs the force and drift ratio values, and a figure shown in Fig. 97 2 is plotted. The last parameter of “units_output” controls the unit system for the output data and figure. Either “N- 98 m” or “lbf-inch” can be input as “units_output” resulting in tw o different unit systems. 99 8 100 Figure 2. The output of sample analysis c ode 1: force-displacement curve for test ID 682. 101 102 The second sample code, “Databas e_Usage_Example2.m” shows how w e can determine all the tests under cyclic 103 loading whose configurations match with each cell in Table E1.3 -1 for CFS framed shear walls sheathed with Wood 104 Structural Panel (WSP) in AISI S400-20. The code reads in all t he test data of shear wall test configurations with 105 Oriented Strand Board (OSB) sheathing and outputs a series of m ean peak forces and corresponding mean drift ratios 106 (both positive and negative loading directions) of tests matchi ng each cell with OSB sheathing configuration in Table 107 E1.3-1 of AISI S400-20 in the command window. In addition, the sample code generates a force-deformation curve 108 plot, as shown in Fig. 3, covering all the shear wall configura tions with OSB sheathing in Table E1.3-1 of AISI S400- 109 20 when parameter “write_switch” is set as 1. This last paramet er of “units_output” plays a similar role to the first 110 sample code. 111 9 112 Figure 3. The output of sample analysis c ode 2: force-displacement curves of all the cyclic tests matching CFS 113 framed OSB sheathed shear wall configurations in Table E1.3-1 o f AISI S400-20. 114 The third sample code, “Database_Usage_Example3.m” aims to filt er out and process all the tests demonstrating a 115 valid detailing per AISI S400-20 , such as a particular type of sheathing (Gypsum Board sheathing adopted herein as 116 an example) or load protocol (cyclic loading chosen in the samp le code), and further plot t he test force-deformation 117 curves with a certain detailing feature in the same figure. Wit hin the database, 348 tests employ a cyclic loading 118 protocol, while 352 tests adopt a monotonic one. With regard to sheathing type, 279 tests utilize wood structural 119 panels; 241, steel sheet sheathing; 117, strap bracing; 40, gyp sum sheathing; and, finally, the remaining 23 tests use 120 other configurations. The third sample code also generates two histogram plots based on absolute peak force per unit 121 length to help understand the shear wall strength value distrib ution. 122 In the third sample code, four i nput parameters, “Sheathing_Inp ut”, “Loading_Input”, “write_switch”, and 123 “units_output”, need to be defined. The default values are take n as “GYP”, “cyclic”, “1”, and “N-m”. This code filters 124 out all the test data with CFS framed shear wall sheathed with Gypsum Board and plots the force-displacement cures 125 10 in the same figure, as presented in Fig. 4. In addition, the th ird sample code also plots all the cyclic testing data in the 126 same figure, as shown in Fig. 5. The parameters, “write_switch” and “units_output”, are similar to the usage method 127 in the first and second sample codes. Furthermore, this code al so generates a histogram for t he absolute peak force per 128 unit length of all the tests within this database, as presented in Fig. 6. To better understand the shear wall strength 129 distribution for tests with different sheathing materials, the third sample code also generates a stacked histogram for 130 absolute peak force per unit length of all the tests, as shown in Fig. 7. 131 132 Figure 4. The output of sample analysis c ode 3: Force-displacement curves of all the CFS fram ed shear wall tests 133 with Gypsum Bo ard sheathing. 134 11 135 Figure 5. The output of sample analysis c ode 3: force-displacement curves of all the CFS fram ed shear wall tests 136 under cyclic loading. 137 138 Figure 6. The output of sample analysis code 3: histogram of absolute pea k force per unit length for all the tests. 139 12 140 Figure 7. The output of sample analysis code 3: tacked histogram of absol ute peak force per un it length for all the 141 tests. 142 DATABASE APPLICATION DISCUSSION 143 The cold-formed steel framed shear wall database has numerous p otential uses. For design specifications, the data 144 may be used to refine strength and drift requirements. In addit ion, the data provides a direct means to assess the 145 overstrength and ductility of shear walls. As one contemplates a more analysis-based path for predicting lateral 146 performance, the data provides a direct means to incorporate te sted shear walls in models. Or the tests can provide 147 benchmarks for high-fidelity models or semi-analytical/phenomen ological model approaches. It is also possible to use 148 the database to assess specific aspects of the nonlinear respon se – for example, cyclic degradation, post-peak slope, 149 and ultimate drift. etc. Further, the database is large enough to assess statistics of response and directly explore 150 component and subsystem reliability. In addition, the database is large enough in size to be used as a training set for 151 modern machine learning methods to predict strength or full she ar-deformation response. The authors are aware of 152 recent additional tests that could also be u sed to further expa nd the database, particularly on new sheathing materials, 153 etc. 154 13 SUMMARY AND CONCLUSIONS 155 A database composed of 700 tested cold-formed steel framed shea r walls has been assembled. Complete descriptive 156 information and lateral force-deformation response are included in the database. The database consists of cold-formed 157 steel framed walls, sheathed with the wood structural panel, sh eathed with steel sheet, braced by straps, with and 158 without gypsum board finish, and a small number of additional m iscellaneous configurations. The database 159 incorporates all necessary information and data, including test configuration information, complete test response, limit 160 states, and American Iron and Steel Institute code prediction i nformation. The basic database structure is introduced, 161 and three example MATLAB codes f or presenting how the database can be utilized are provided. The database 162 provides important and useful information to advance the unders tanding and modeling of lateral force-resisting 163 systems in cold-formed steel framing. 164 ACKNOWLEDGMENTS 165 Building this database has included generosity and help from a large number of people. Postdoctoral researcher Dr. 166 Deniz Ayhan Moen initiated the first version of the database an d participated in the ASCE 41 analysis using the first 167 version. Master’s student Sam Baer contributed to the expansion of the main database, and doctoral student Dr. Fardad 168 Haghpanah provided significant error-checking when he was utili zing the database. Professor Cheng Yu provided 169 source data not publicly available to improve the database info rmation. Professors Tara Hutchinson and Kara Peterman 170 in the CFS-NHERI effort provided feedback on the database and i ts application along with their doctoral students 171 Amanpreet Singh, Hernan Casteneda and Fani Derveni. In addition , several members of the Lateral Committee at the 172 American Iron and Steel Institute have provided feedback on the database and its application. This work is in part, 173 part of the research project, Seismic Resiliency of Repetitivel y Framed Mid-Rise Cold-Formed Steel Building (CFS- 174 NHERI) which is supported by the National Science Foundation un der Grant No.1663348 and No.1663569. Any 175 opinions, findings, and conclusions or recommendations expresse d in this material are those of the author(s) and do 176 not necessarily reflect the views of the National Science Found ation or others acknowledged. The authors would like 177 to express gratitude for the generosity of the original researc hers of all these shear wall tests. 178 14 DECLARATION OF CONFLICTING INTERESTS 179 The author(s) declared no potential conflicts of interest with respect to the research, author ship, and/ or publication of 180 this article. 181 DISCLAIMERS 182 Any opinions, findings, and conclusions or recommendations expr essed in this publication are those of the authors 183 and do not necessarily reflect the views of the sponsors and em ployers. 184