SBIR Phase I: Hardness Strength and Ductility Tester for Field Assessment of Structures

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This Small Business Innovation Research Phase I project will support commercialization of a portable instrument capable of probing the hardness, strength and ductility of existing infrastructure without service interruption. Catastrophic failures of pipelines, buildings and bridges result in loss of life and billions of dollars in repair, remediation, and liability. The Pipeline and Hazardous Materials Safety Administration (PHMSA) estimated the total cost incurred to remediate pipeline failures at $7 billion over the past 20 years. The new portable instrument will enhance the ability of those responsible for integrity management and condition assessment to prevent accidents and failures by determining the pressure capacity of pipelines for which original quality records are unavailable. It will be a safer, less invasive, and more economical alternative to removing a sample of material for laboratory testing. It will supersede existing in-field surface mechanical assessment based on indentation hardness testing. The initial market size for characterization services to oil and gas pipelines is $25 million per year. Additional applications for condition assessment of transportation, energy and naval infrastructures are expected. The instrument may also serve in quality control testing for imported steel products and for advanced manufacturing industries including aerospace. The intellectual merit of this project includes the transfer from laboratory to field service of a contact mechanical test of frictional sliding to measure mechanical properties of materials. Measurements from the new instrument serve as an input into non-empirical predicting equations for the material stress strain curve. The equations are adapted from previous academic research where parametric finite element and dimensional analysis provide a unique material stress strain curve from measured characteristics of the residual surface profile. Unlike indentation hardness, frictional sliding allows for continuous characterization of gradients in properties through welded joints, a frequent location of field failures. This project improves upon existing concepts of stylus self-alignment and field surface profiling techniques with the objective to validate accuracy of the instrument for the pipeline integrity market. The main effort includes integrating instrumentation to measure the material response with the action of sliding the stylus on the surface. Also, a dual-stylus unit will be implemented to improve the instrument accuracy through acquiring the material response to two different geometries of contact. Through this research, a prototype field testing unit will be implemented for further validation testing of the method for use on pipeline infrastructures.