This model accounts not only for the rapid increase of creep at high compressive stress (flow) but also for the decrease of creep observed for subsequent load increments after a long period of low sustained compressive stress (adaptation). A simply supported column is analyzed for typical load histories: sustained loading; short-time loading to failure; and sustained load followed by short-time loading to failure. Numerical results confirm that the flow nonlinearity makes the column fail in a finite time and the adaptation nonlinearity makes the response to the short-time load applied after a long period of a low sustained load stiffer. Also, there is a substantial difference in the column strength for the same load duration depending upon the loading history, especially the ratio of constant sustained load (dead load) and short-time load (live load) and their durations. This could be taken into account in setting the safety factors for columns subjected to dead and live loads of various ratios.
|Original language||English (US)|
|Number of pages||23|
|Journal||ASCE J Struct Div|
|State||Published - Jan 1 1980|
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