![]() From the figure, it is clear that the residual strength was not influenced by the incident impact energy up to some energy levels (2.242 J for SC10 and 2.467 J for SC20). The residual strength data, normalized by the mean strength of the unimpacted sandwich panels, are plotted against impact energy in Fig. Next, to identify the reduced strength of sandwich panels with impact-induced damage, three point flexural tests were conducted for the impacted sandwich panels subjected to incident impact energies in the range of 2.18–8.85 J for SC10 and 2.19–13.1 J for SC20. While such an approach can be fairly effective for assessing the distribution of residual strength of impacted composite materials, the approach does not take into account the distribution of flexural strength in unimpacted materials which may affect the distribution of residual strength, but does use only the residual strength itself. Also, the authors 8,9 have analyzed the statistical properties of residual strength of composite structures subjected to low velocity impact The random variable was employed to represent the variation of residual strength with incident impact energy, into Caprino's residual strength prediction model, 10 and this model could successfully evaluate the distribution of residual strength in composite materials with impact-induced damage under flexural loading. They have showed that the hybrid fiber-reinforced concrete had some variation in the impact strength but they did not develop statistical model to describe the variation of impact strength. 7 have statistically investigated the first-crack strength, failure strength, and strength reliability of steel–polypropylene hybrid fiber-reinforced concrete under drop weight impact loading. 6 have shown that compression-after-impact (CAI) strength of glass knitted have a significant scatter, but they also did not examine the probabilistic properties of CAI strength. Shim and Yang 5 have shown that there is some variation in the residual strength of carbon/epoxy laminates with impact damage, but they did not mention the probabilistic characteristics of the residual strength or its mechanism. 4 have shown that there is significant scatter in the residual tensile strength and statistically analyzed the residual tensile strength. Abstract reprinted with permission of Elsevier.To address this, many pieces of research have analyzed the statistical behavior of composite materials with impact-induced damage. Find a library where document is available.However, bridges with high skews and bridges evaluated using ultimate capacity from detailed finite element analysis, regardless of skew, will receive unnecessarily conservative flexural capacity ratings if response fractions are relied upon to represent analogous internal load effects. Bridges with small skews evaluated using only elastic analysis were found to be reasonably well characterized using response fractions feasibly obtained from diagnostic load tests. The analyses indicated that neglecting concrete cracking noticably affected capacity by overestimating slab plate flexure between abutments, resulting in increasingly unconservative reserve capacity evaluations with increasing skew. Results are also presented for the 60° case with linear elastic deck to directly compare the influence of cracking versus non-cracking deck. Concrete deck is modeled with a tension cracking stress limit consistent with typical design assumptions in United States practice. Skew is varied parametrically from 0° to 60°. Analytical models, accounting for material inelasticity in the steel girders, are constructed for each of two experimentally tested bridges. Additionally, this study provides a secondary benefit by comparing the applicability of two general load distribution characterization methods: response fractions (displacement, strain, or curvature ratios) versus extracted and integrated results from a rigorous analytical model. Structural behavior is examined throughout the range of potential applied loads, from initial linear elastic behavior to initial yielding and ultimate conditions. The primary objective of this study is to characterize the influence of concrete deck nonlinearity on 3D system behavior and capacity of skewed steel girder bridges. More rigorous methods can reveal significant unquantified reserve capacity with 3D system behavior as ductile members experience yielding, but reserve capacity can be overestimated if cracking in a concrete deck is neglected. Nonlinear Flexural Distribution Behavior and Ultimate System Capacity of Skewed Steel Girder Bridgesīridge designs are routinely developed using simplified 1D approximations of structural behavior and assume linear elastic behavior throughout the structure.
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