To investigate the mechanical behavior of composite beams under pure torsion, considering the torsional contribution of the steel beam flanges, we established finite element models of I-steel-concrete composite beams. The nonlinear material constitutive relationship of concrete and steel was adopted in the model, and we validated the relationship by tests. Afterward, parametric analyses were carried out to study the main factors affecting the torsional performance of the composite beam. Our primary investigation focused on the composite effects and load sharing ratio of the steel beam and the concrete slab under pure torsion. We established the formulas for obtaining the maximum shear stresses in the concrete slab and the steel beam based on the composite effects and superposition principle. From these tests and our calculations, we proposed a model defining the torsional bearing capacity and the torsional stiffness of the I-steel-concrete composite beam; thus, the torsional contribution of the concrete slab and the steel beam were a primary concern in this research. Bearing capacity formulas are also proposed herein and are comparable with those in the literature, demonstrating that our formulas, with simple forms, are highly reliable when predicting the torsional behavior of the composite beam.
To obtain uniform and controllable material removal on hard and brittle materials, a novel processing technology with functionally graded lapping and polishing plate (FG-LPP) was proposed. Taking application of particles/rubber composites and adjustable contact stress of workpiece as key point, the abrasive particles and rubber were mixed with different mass ratios; then the FG-LPP was formed with characteristics of required quasi-continuous distribution of Young’s modulus in the radial direction by two-step processing technique. The properties of Young’s modulus, loss factor, and glass transition temperature of different particles/rubber composites were tested and calculated. Through comparison and analysis, silicon carbide (SiC)/chloroprene rubber (CR) composites are the suitable application object of FG-LPP. Moreover, by laser particle size analyzer, scanning electron microscope, and X-ray diffraction, the size distribution of abrasive particles, micromorphology of particles/rubber composites and their phase composition were tested respectively to better reveal the structure and properties. The test results indicate that under the action of ZnO and MgO, CR undergoes a vulcanization reaction gently and forms a spatial three-dimensional structure. Thus, it helps to increase the intermolecular distance and weaken the intermolecular forces because the NO is easy to enter the CR molecules, which improves the intermiscibility between SiC and CR.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.