Abstract. The flexural strength of ice surfaces bonded by freezing, termedfreeze bond, was studied by performing four-point bending tests of bondedfreshwater S2 columnar-grained ice samples in the laboratory. The sampleswere prepared by milling the surfaces of two ice pieces, wetting two of thesurfaces with water of varying salinity, bringing these surfaces together,and then letting them freeze under a compressive stress of about 4 kPa. Thesalinity of the water used for wetting the surfaces to generate the bondvaried from 0 to 35 ppt (parts per thousand). Freezing occurred in air under temperatures varyingfrom −25 to −3 ∘C over periods that varied from 0.5 to∼ 100 h. Results show that an increase in bond salinity ortemperature leads to a decrease in bond strength. The trend for the bondstrength as a function of salinity is similar to that presented in Timco andO'Brien (1994) for saline ice. No freezing occurs at −3 ∘C oncethe salinity of the water used to generate the bond exceeds ∼ 25 ppt. The strength of the saline ice bonds levels off (i.e., saturates)within 6–12 h of freezing; bonds formed from freshwater reach strengthsthat are comparable or higher than that of the parent material in less than0.5 h.
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Subject-specific strength percentile determination for two-dimensional symmetric lifting considering dynamic joint strength
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The transverse tensile strength of composites is susceptible to size effects. Therefore, it is paramount to develop length-scale specific physical test procedures to validate computational models that estimate the transverse composite response using micromechanics. To this end, a computational process modeling and virtual mechanical testing framework are presented in this study to predict the transverse response of composite microstructures subjected to processing conditions. Informed by a comprehensive material dataset, the numerical model is shown to reliably predict the process-induced residual stress generation in composite microstructures and accurately evaluate its influence on their transverse strength prediction. A novel procedure to fabricate thin composite laminates from a single ply of carbon fibers and characterize their transverse tensile response is presented to validate the numerical model. The results show excellent agreement with the virtual test predictions. This study highlights the importance of length-scale specific testing to minimize the influence of size effect on the transverse composite strength.more » « less