NASA LogoNTRSNTRS - NASA Technical Reports ServerSearchmore_vertCollectionsAboutNewsHelpLogin Back to ResultsDrawbar Pull (DP) Procedures for Off-Road Vehicle TestingAs NASA strives to explore the surface of the Moon and Mars, there is a continued need for improved tire and vehicle development. When tires or vehicles are being designed for off-road conditions where significant thrust generation is required, such as climbing out of craters on the Moon, it is important to use a standard test method for evaluating their tractive performance. The drawbar pull (DP) test is a way of measuring the net thrust generated by tires or a vehicle with respect to performance metrics such as travel reduction, sinkage, or power efficiency. DP testing may be done using a single tire on a traction rig, or with a set of tires on a vehicle; this report focuses on vehicle DP tests. Though vehicle DP tests have been used for decades, there are no standard procedures that apply to exploration vehicles. This report summarizes previous methods employed, shows the sensitivity of certain test parameters, and provides a body of knowledge for developing standard testing procedures. The focus of this work is on lunar applications, but these test methods can be applied to terrestrial and planetary conditions as well. Section 1.0 of this report discusses the utility of DP testing for off-road vehicle evaluation and the metrics used. Section 2.0 focuses on test-terrain preparation, using the example case of lunar terrain. There is a review of lunar terrain analogs implemented in the past and a discussion on the lunar terrain conditions created at the NASA Glenn Research Center, including methods of evaluating the terrain strength variation and consistency from test to test. Section 3.0 provides details of the vehicle test procedures. These consist of a review of past methods, a comprehensive study on the sensitivity of test parameters, and a summary of the procedures used for DP testing at Glenn.Document ID20170010706Acquisition SourceGlenn Research CenterDocument TypeTechnical Publication (TP)AuthorsCreager, Colin*(NASA Glenn Research Center Cleveland, OH, United States)*Asnani, Vivake*(NASA Glenn Research Center Cleveland, OH, United States)*Oravec, Heather*(Akron Univ. Akron, OH, United States)*Woodward, Adam*(Virginia Polytechnic Inst. and State Univ. Blacksburg, VA, United States)*Date AcquiredNovember 7, 2017Publication DateAugust 1, 2017Subject CategoryGround Support Systems And Facilities (Space)Statistics And ProbabilityEngineering (General)Report/Patent NumberGRC-E-DAA-TN31725NASA/TP-2017-219384E-19292Funding Number(s)CONTRACT_GRANT: NNC13BA10BWBS: WBS 647280.04.03.20CONTRACT_GRANT: NNX11AC94GDistribution LimitsPublicCopyrightPublic Use Permitted.Keywordswheeldrawbar pullterramechanicsoff-roadtractiontiremobilityAvailable DownloadsNameType20170010706.pdfSTIcloud_downloadcontent_copyvisibilityRelated RecordsThere are no records associated with this record.visibility_offNo Preview Available
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