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原文传递 Design, Development, and Testing of Advanced Bridge Structures; Final rept. May 90-Jun 93

题名：	Design, Development, and Testing of Advanced Bridge Structures; Final rept. May 90-Jun 93
作者：	McNamara, D.; DasGupta, A.; Hand, H.; Maisano, J.; Arah, C.
关键词：	Adhesive bonding; Adhesives; Bridges; Cleaning; Construction; Curing; Degradation; Figure of merit; Finite element analysis; Lightweight; Low temperature; Models; Moisture; Optimization; Overlap; Repair; Stress concentration; Surfaces; Thickness; Toughness; Viscosity; Loads(Forces); Composite materials; Bonded joints; Test and evaluation; Design criteria; Fracture(Mechanics); Embedding; Shear stresses; Tensile strength; Strength(Mechanics); Epoxy resins; Hardening; Composite structures
摘要：	Three aspects of the application of adhesive bonding to lightweight bridge structures were examined: producing composite surface treatments to reliably bond with epoxy adhesives, developing computer models to optimize adhesive joint design and develop design guidelines, and adapting a high-toughness, low-temperature-curing epoxy adhesive to practical use as a bridge and repair kit adhesive. New testing methods were developed in the composite surface preparation task to assess fracture toughness and environmental durability of composite-to-adhesive bonds. A wide variety of existing and novel surface treatments were examined. Simple mechanical cleaning, such as hand sanding, was shown to be highly effective in providing the basis for strong, tough, and durable bonds. Finite element models of a prototype tubular lap joint indicated that such a joint could be characterized by a few critical parameters, such as diameter, tube thickness, and joint overlap length. Design guidelines were developed using these parameters to allow a designer to determine load bearing capacity, optimum design, and stress-concentration factor (a figure of merit). Design optimization studies included techniques to reduce stress concentrations and equalize load across the entire surface of the joint. Adhesive enhancement studies resulted in the development and limited production of a lower viscosity, repair-kit suitable version of a high toughness, low-temperature-curing epoxy adhesive originally developed on an earlier research program. Studies of potential sealant systems to prevent degradation of epoxy adhesives due to moisture ingress did not identify any suitable sealants. Adhesive bonding, Composite surface preparation, Finite element analysis, Adhesive joint design guidelines, Structural epoxy adhesives.
总页数：	199p
报告类型：	科技报告