A study of process-induced stress and deformation in thick-section thermosetting composite laminates is presented. A methodology is proposed for predict ing the evolution of residual stress develop...

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Process-Induced Stress and Deformation in Thick-Section Thermoset Composite Laminates:

A review of the recent developments in the analysis of laminated beams and plates with an emphasis on shear effects and buckling is presented. A discussion of various shear-deformation theories for plates and beams is given. The available theories are derived assuming a variation of either the in-plane displacement components or the stress components or both in the thickness coordinate. A review of the recently developed finite elements to analyze thin and thick laminated beams and plates is given next. These elements have been derived using the displacement methods, or the mixed methods or the hybrid methods. Recent studies on the buckling and postbuckling behavior of perfect and geometrically imperfect plates are described next. These behaviors have been studied using analytical, numerical, and experimental techniques. Finally, a review of the various studies on the delamination buckling and growth in beams and plates is given. Once again, the studies have been conducted using analytical, numerical, and experimental techniques. The energy release rates have been determined using closed-form solutions or using numerical differentiation. Mention also is made of studies on multiple delaminations and on dynamic response of composite laminates under impact loads.

Recent advances in analysis of laminated beams and plates. Part I - Sheareffects and buckling.

A finite element formulation is presented for modeling the dynamic as well as static response of laminated composites containing distributed piezoelectric ceramics subjected to both mechanical and electrical loadings. The formulation was derived from the variational principle with consideration for both the total potential energy of the structures and the electrical potential energy of the piezoceramics. An eight-node three-dimensional composite brick element was implemented for the analysis, and three-dimensional incompatible modes were introduced to take into account the global bending behavior resulting from the local deformations of the piezoceramics. Experiments were also conducted to verify the analysis and the computer simulations. Overall, the comparisons between the predictions and the data agreed fairly well. Numerical examples were also generated by coupling the analysis with simple control algorithms to control actively the response of the integrated structures in a closed loop.

Finite element analysis of composite structures containing distributed piezoceramic sensors and actuators

For bridge owners faced with a rising number of structurally deficient steel bridges, the rehabilitation of steel girders using advanced composite materials offers an attractive solution for short-term retrofit or long-term rehabilitation. Several laboratory studies conducted at the University of Delaware have shown that carbon fiber-reinforced polymer (CFRP) plates can be used to effectively strengthen steel bridge girders. Initial studies focused on several issues including the effect on global stiffness and strength, bond force transfer and development, and environmental and fatigue durability of the CFRP/steel bond. Once the feasibility of the strengthening procedure had been thoroughly examined, strengthening of an existing steel bridge girder was performed. This paper reviews the research conducted to date, and presents details of a demonstration of this technology performed on a bridge located on Interstate 95 in Newark, Del.

Strengthening of a steel bridge girder using cfrp plates

Compositions comprising elastomeric polyurethane prepolymers comprising the reaction product of at least one diisocyanate selected from the group consisting of p-phenylene diisocyanate, m-phenylene diisocyanate, 1,4-cyclohexyl diisocyanate, tetramethylxylyl diisocyanate and dimethylphenyl diisocyanate and at least one polyol or polythiol characterized by the presence of two hydroxyl or thiol groups or one hydroxy and one thiol group; a monomeric diol or dithiol curing agent and vein forcing fiber are especially useful for preparing fiber-reinforced composite structures, especially for dynamic applications.

Fiber reinforced composites

Preface to the Second Edition. Preface to the First Edition. 1. Introduction to Composite Materials. 2. Anisotropic Elasticity and Composite Laminate Theory. 3. Plates and Panels of Composite Materials. 4. Beams, Columns and Rods of Composite Materials. 5. Composite Material Shells. 6. Energy Methods For Composite Material Structures. 7. Strength and Failure Theories. 8. Joining of Composite Material Structures. 9. Introduction to Composite Design. Appendices: A-1. Micromechanics. A-2. Test Standards for Polymer Matrix Composites. A-3. Properties of Various Polymer Composites. Author Index. Subject Index.

C. W. Bert

Papers

The behavior of structures composed of composite materials