Introduction Of Adhesively bonded lap joints from pultruded
Source:未知Author:admin Addtime:2018-02-02 15:16 Click:
Fiber-reinforced polymer (FRP) composites are increasingly Pultrusion Profiles used in engineering structures thanks to theiradvantageous material properties such as such a highspecific strength, large insensitivity to frost and de-icingsalts, and rapid installation of components [1]. The advancesin pultrusion technology allow the production of large-scalestructural profiles with acceptable cost for civil infrastructureapplications. However, structural FRP components arestill difficult to connect due to the brittle fibrous andanisotropic nature of the materials. The current practiceof bolting leads, in most cases, to an over-sizing of thecomponents. Adhesive bonding is therefore more appropriatefor FRP composites. Adhesive joints show higherjoint efficiencies and are much stiffer compared tobolted joints. This is of importance with regard tothe stiffness-governed design of structures using glass fibers the stiffness-governed design of structures using glass fibers (GFRP) [2]. Furthermore, the load transfer in adhesive joints is more uniform with fewer stress concentrations as compared with bolted joints. Without holes the adherends
remain undamaged; holes are points where moisture ingress can occur, which can affect durability [3].
In order for adhesive bonding to be used in the design of FRP load-carrying structures, joint strength must be predictable as a function of the material properties, the joint geometry and the type of loading (includingenvironmental impact). The failure behavior must also be understood. A prerequisite for the successful prediction of joint strength is the understanding of the stress-strain state in the joint. The stress–strain state can be determined either
analytically, by solving the differential equations describing the mechanics and kinematics of the joint, or numerically by the use of Finite Element Analysis (FEA). In contrast with existing analytical solutions, FEA enables the consideration of important geometrical details such as chamfers and fillets, or non-linear and anisotropic。
