Author(s): Robert M. Adamson; John P. Dempsey
Linked Author(s): John Dempsey
Keywords: No Keywords
Abstract: Presently, experimental information regarcung the mechanical behavior of sea ice consists of both laboratory experiments and field scale measurements. The laboratory tests have been done on small sized, possibly subsized, samples where questions of heterogeneity are an issue and extrapolation to larger scale behavior is in question. The large scale behavior of events such as thermal fracturing and ridging is·typically based on acoustical measurements and observations, lacking a sound mechanical background. A large gap exists at the intermediate scale of 1 m to 1 km where very little information is 'available, prompting a thorough arctic field program designed to investigate test sizes from O. lm to 100m. Six field trips were completed, testing freshwater and sea ice with varying thickness, temperature profile, c-axis alignment and size. All of the large scale experiments were completed in situ retaining the inherent temperatme, density and salinity of the sea ice. Cyclic and creep recovery sequences of loading were imposed on selected experiments to extract constitutive information necessary for the purposes of modeling. Rate effects were also investigated through a series of monotonic load ramps with varying rates. A final load or crack opening displacement controlled ramp was applied to fracture the sample. An extensive small scale program (in the field and in the laboratory) was also completed in an effort to link the large scale experiments with existing laboratory investigations. The extensive amount of information gathered from the field investigations provides the means necessary for validating existing models and size effect predictions. Experimental results of the cyclic, creep-recovery and fracture measurements are given. In the paper by Mulmule, Adamson and Dempsey (in this volume), the modeling of the small and large scale data currently in progress at Clarkson University is discussed. The modeling incorporates a. cohesive zone model coupled with viscoelastic material behavior.
Year: 1996