7 Replies Latest reply: Sep 24, 2004 12:00 AM by ptc-1368288 RSS

    Dynamics, response of SDF system

    BillWadsworth Bronze
      The attached sheet provides the
      elastic-plastic response of a
      single degree of freedom system acted upon by a transient load.
        • Dynamics, response of SDF system
          ptc-1368288 Copper
          From your original work sheet, we get nothing !
          Here, it plots all ... no idea if correct ?

          jmG
          • Dynamics, response of SDF system
            ptc-1368288 Copper
            On 9/24/2004 2:22:38 PM, sakiss wrote:
            >If I define J to have "NO"
            >members in the vector, I still
            >need NO + 1 to define delta p.
            >
            >I tried the above fix of
            >defining a "j" variable with
            >"NO" members and I still get
            >an error.
            >
            >I also tried to define
            >J:1;(no+1) and still get an
            >error. I get an �illegal
            >context� message.
            _______________________

            Don't post *.doc ... post *.mcd !

            Did you open my reply ?

            jmG



            • Dynamics, response of SDF system
              superres Silver
              On 9/24/2004 2:22:38 PM, sakiss wrote:
              >If I define J to have "NO"
              >members in the vector, I still
              >need NO + 1 to define delta p.
              >
              >I tried the above fix of
              >defining a "j" variable with
              >"NO" members and I still get
              >an error.
              >
              >I also tried to define
              >J:1;(no+1) and still get an
              >error. I get an �illegal
              >context� message.

              That's because you didn't replace ALL instances of i in the definition


              TTFN,
              Eden
              • Dynamics, response of SDF system
                Copper
                I loaded this file and it seems that the spreadsheet has 2 problems with variable definition. - see attached word doc.
                  • Dynamics, response of SDF system
                    TomGutman Silver
                    You just need an older version of Mathcad. There was a change made so that multiplication by zero no longer prevents the evaluation of the second operand. So now if you need to have an expression evaluated only under some conditions you need to use an explicit if statement.

                    And there is only one problem in the sheet -- everything else traces back to that single error.

                    Tom Gutman
                    • Dynamics, response of SDF system
                      superres Silver
                      On 9/24/2004 12:46:15 PM, sakiss wrote:
                      >I loaded this file and it
                      >seems that the spreadsheet has
                      >2 problems with variable
                      >definition. - see attached
                      >word doc.

                      It's rather trivial to fix. define j:1;No and replace i with j in the definition of delta_p


                      TTFN,
                      Eden
                    • Dynamics, response of SDF system
                      Copper
                      If I define J to have "NO" members in the vector, I still need NO + 1 to define delta p.

                      I tried the above fix of defining a "j" variable with "NO" members and I still get an error.

                      I also tried to define J:1;(no+1) and still get an error. I get an �illegal context� message.