In this work, we present an approach of deconvolution ill-posed problems of superimposed signals in time. A priori information must be taken into account to solve this problem. The a priori information translates the physical properties of the ultrasonic signals. The defect impulse response is modelled as a Bernoulli-Gaussian sequence. Deconvolution becomes the detection problem of the optimal ...

The article presents the methodology for finding material damping properties at higher frequency and at relatively lower amplitudes. The method employs combined Finite element and frequency response for finding the damping characteristics of composite materials, which are used in high frequency applications. The hybrid method has been implemented on carbon fiber reinforced polymer (CFRP) and gl...

The interlaminar fracture toughness in pure mode II (GIIc) of a Carbon-Fibre Reinforced Plastic (CFRP) composite is characterized experimentally and numerically in this work, using the End-Notched Flexure (ENF) fracture characterization test. The value of GIIc was extracted by a new data reduction scheme avoiding the crack length measurement, named Compliance-Based Beam Method (CBBM). This meth...

the current study is focused on strengthening of reinforced concrete (rc) beams using cfrp straps installed in pre-cut grooves. the method which is referred as near surface mounted (nsm) benefits considerable advantages in comparison with the conventional externally bonded reinforcement (ebr) method and provides better normal and shear stress transfer between the frp and concrete substrate. the...

In this paper, a technique based on a new model from finite differences discretization of Fourier heat propagation in 3D, is presented in order to be applied on a sequence of infrared images to enhance contrast and automatically detect and characterize flaws in composite slabs. The performance of this technique is evaluated using artificial thermal sequences from a simulated CFRP slab generated...

The present paper investigates the response a sandwich composite laminate that involves intraply hybrid carbon fiber reinforced polymer (CFRP)/Dyneema core under impact and post-impact tests. This was designed to gain high elasticity stiffness/weight ratio of Dyneema fibers while maintaining structural integrity CFRP at core. Low-velocity compression after tests were employed evaluate damage re...

In the present study, a new method for retrofitting reinforced concrete beam is introduced in which steel-concrete composite jackets containing steel fiber is used. For this purpose, 75% of the peripheral surface of reinforced concrete beams was initially reinforced using steel plates and bolts, and steel fiber reinforced concrete was used between the steel plates and the peripheral surfaces of...

Carbon fiber reinforced plastic (CFRP) composite materials have favorable mechanical and physical properties such as low density, high strength-to-weight ratio, fatigue resistance creep behavior, stiffness. Thanks to these unique properties, they produce aircraft parts outer flaps, carry-through structures, center wing boxes automotive body panels, engine components, structure members. However,...

This paper examines the impact of flexural strengthening on percentage damaged strands in internally unbonded tendons partially prestressed concrete beams (0, 14.28%, and 28.57%) recovering conditions using CFRP composite longitudinal laminates at soffit, end anchorage U-wrap sheets to restore original capacity mitigate delamination soffit Carbon Fiber Reinforced Polymer (CFRP) laminates. The c...

Composite/metal stack materials, which have excellent mechanical properties, are wideyl used in aerospace industry. However, their machining operation is challenging due to two different material. In this study materials consisting of CFRP and Al 7075-T6 were drilled with drilling parematers investigate delamination defect, thrust force, inner surface roughness hole wear the cutting tool. Cutti...