A completely nondestructive means of r-value measurement is being developed. Unlike the modul-r method, it requires no specimen removal and has potential for on-line measure-ment. The method employs noncontacting ultrasonic transducers which generate waves propagating at three different angles relative to the sheet rolling direction. A prototype instrument based on these principles has been jointly developed by researchers at Ford Motor Company and National Institute of Standards and Technology (NIST).At present, there are correlations between ultrasonic and mechanical measurements of r̄. The ultrasonic measurements generally agree with mechanical measurements to 0.1 or better. A method based on metallurgical theories is being developed to use ultrasonic velocity measure-ments to predict not only r̄, but individual r values.To date, all measurements have been made on static sheet. We are currently developing a device to move sheet metal at controlled velocity. This will allow simulation of on-line operation, as in a rolling mill. In addition, a circuit has been developed to automate the velocity measurements and transmit them to a computer. The eventual goal is to predict r-values from these measurements, using metallurgical theories. The predictions should be done in about 1 s, allowing for possible on-line measurement and control of r-value.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Progress Towards Nondestructive, On-Line Measurement of Sheet Metal Formability


    Additional title:

    Sae Technical Papers


    Contributors:
    Clark, A. V. (author) / Hirao, M. (author) / Izworski, N. (author) / Cohen, Y. (author)

    Conference:

    International Congress & Exposition ; 1991



    Publication date :

    1991-02-01




    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English




    Progress towards nondestrusive, on-line measurement of sheet metal formability

    Clark,A.V. / Izworski,N. / Hirao,M. et al. | Automotive engineering | 1991


    Ultrasonic measurement of sheet anisotropy and formability

    Clark,A.V. / Thompson,R.B. / Reno,R.C. et al. | Automotive engineering | 1989


    Formability Criteria for Selecting Sheet Metal Lubricants

    Nine, Harmon D. / Siekirk, John F. / Keeler, Stuart P. | SAE Technical Papers | 1988


    Formability criteria for selecting sheet metal lubricants

    Keeler,S.P. / Nine,H.D. / Siekirk,J.F. et al. | Automotive engineering | 1988


    Ultrasonic Measurement of Sheet Anisotrophy and Formability

    Clark, A.V. / Matlock, D. / Blessing, G.V. et al. | SAE Technical Papers | 1989