Reinforced interface and mechanical properties of high strength carbon fiber composites

Based on the surface analysis of carbon fiber, an epoxy resin matrix with good wettability to carbon fibers had been developed and studied, and the influence of winding tension on the interface and mechanical properties of the composite were studied. The surface morphology of carbon fiber and the active functional groups of sizing agent were analyzed. In order to form a good interface combination, the wettability between carbon fibers and epoxy resin matrix was characterized by dynamic contact angle. The winding tension played an important role in the mechanical properties of composites. Therefore, a kind of carbon fiber reinforced composites, Naval Ordnance Laboratory (NOL) rings were fabricated using different winding tensions. Particularly, when the winding tension was 30 N, the interfacial bonding between carbon fibers and resin matrix was the most compact and firm. The tensile strength and interlaminar shear strength (ILSS) of NOL rings reached high values, 2712 MPa and 75 MPa, respectively.

ANALYSIS OF MOTOR SPEED EFFECT ON WINDING TENSION IN THE WIND UP CALENDERING PROCESS

The winding process is widely used in manufacturing industries. For the high speed winding, the centre winding method is used. Irregular internal stresses at the centre of the roll result in major weaknesses such as buckling, spoking and cinching. Therefore, entanglement with the right tension is very important to get a stable wound package. It should be mentioned that winders usually operate based on the principle of precision winding. A typical characteristic of winders is increasing the surface speed as the diameter increases. This will cause the winding to increase which has the potential to cause damage. To overcome damage due to an increase in roll tension, the rolling motor speed must decrease so that the roll tension remains the same or even decreases. And because the rolling process uses additional media in the form of a liner fabric which is tension controlled with pneumatic disc brake, the pressure brake must also be made taper constructing both.

Study on Mechanical Behavior of Tensile Armor Wires of Marine Flexible Pipes and Cables During Winding Process

In this paper, a mechanical model of armor wire winding process is established to quantify the relationship between the tension force and the internal force of armor wire cross section in winding process. Then based on this model, a method for predicting the residual stress of armor wire cross section after winding is presented. The reasonable winding tension force and the minimum residual stress are discussed. In addition, the reasonable design of the processing equipment is further discussed. This paper provides a useful reference for the evaluation of key parameters and the prediction of residual stress in the processing of tensile armor layer of offshore flexible pipes and cables.