Mohamed S. Gaith and Imad Alhayek Department of Mechanical Engineering, Al-Balqa Applied University, Amman, Department of Applied Sciences, Al-Balqa Applied University, Amman Jordan 1. Introduction Most of the elastic materials in engineering are, with acceptable accuracy, considered as anisotropic materials; metal crystals (due to the symmetries of the lattice), fiber-reinforced composites, polycrystalline textured materials, biological […]
Category: ADVANCES IN COMPOSITE MATERIALS – ECODESIGN AND ANALYSIS
Design formulae
The fracture energy, rF, depends on both the strength properties of adherents, concrete and adhesive, and the properties of the concrete surface. When the reinforcement is correctly applied, the detachment of the reinforcement occurs with debonding in the concrete layer and the specific fracture energy of the interface law can be written in a form […]
Experimental results
A total of 58 SST tests in four sets (i. e. I-12 tests, II-16 tests, III-12 tests, IV-18 tests) were performed on CFRP plates (38) and sheets (20) applied on two opposite longitudinal faces of 29 concrete prisms. Concrete mix was specifically designed to obtain low compressive concrete strength to simulate the FRP application on […]
Experimental testing techniques and results
As stated above, the effectiveness of FRP externally bonded on RC members is strongly related to the interface behaviour that depends on the mechanical and geometrical properties of materials. Thus an FRP-to-concrete bond strength model is the key to the accurate prediction of debonding failures in FRP-strengthened RC beams, including plate end debonding failures and […]
Solutions in the nonlinear range
The assumption introduced in the subsection 2.2 for simplifying the general eighth-order equation formulated in subsection 2.1 can be generally assumed as a reasonable trade-off between the (good) accuracy of the obtained model and the (higher) simplicity of its equations. The approximation introduced by the supplementary assumption is generally accepted especially in the nonlinear range, […]
Possible simplifications of the general model
The general model formulated in the previous section can be simplified by introducing further assumptions about the geometric and mechanical assumptions. In particular, a key simplification derives in the case of negligible thickness tf of the FRP laminate, if compared, for instance, with a suitable reference value of the length. In particular, it is possible […]
Theoretical models
An analytical formulation for modelling the behaviour of the FRP-to-concrete adhesive interfaces is presented and discussed in the present section. The behaviour of FRP-to – concrete joints in the linear range is examined in the first subsection. Then, the aspects more directly related at the ultimate behaviour are addressed in the second one. 1.1 A […]
On the Behavior of FRP-to-concrete Adhesive Interface: Theoretical Models and Experimental Results
Enzo Martinelli, Antonio Bilotta, Ciro Faella and Emidio Nigro Department of Civil Engineering, University of Salerno, Fisciano (SA), Department of Structural Engineering, University of Naples "Federico II", Naples Italy 1. Introduction Fiber-reinforced polymers (FRP) are more and more commonly employed for strengthening existing structures of both reinforced concrete (RC) and masonry. Since FRP sheets (cured […]
Numerical results
Experimental results are compared with those obtained by numerical simulations. The damage criterion has been implemented inside ANSYS code to evaluate current dimension of the defect varying the number of cycles; the mesh is implemented by square elements. External load is applied at the top of loaded layer; the constraints are placed in appropriate way […]
Third campaign of experimental test (bonded joints Al-Al)
Specimens made of two aluminium layers 2024 T3 are used For MMELS tests (Mixed Mode End Load Split) and DP760 3M epoxy adhesive is used (Ducept, Gamby & Davies, 1999; Pirondi & Nicoletto, 2001). epoxy adhesive 2024 T3 aluminium alloy Shear strength [MPa] 28.2 Ultimate strength [MPa] 448 Peel strength [N/cm2] 61.6 Yield strength [MPa] […]