A composite test coupon includes a plurality of plies. The plurality of plies include first ply layers and second ply layers. The first ply layers have first fibers and a substantially uniform matrix material associated with the first fibers. The second ply layers have second fibers and a pre-stressed matrix material associated with the second fibers. The first fibers are oriented in a first direction, and the second fibers are oriented in a second direction that is different from the first direction. The pre-stressed matrix material includes stress induced cracks between the second fibers of each of the second ply layers.

A racquet extending along a longitudinal axis and including a frame including a head portion, a handle portion, and a throat portion. The head portion forms a hoop that defines a string bed plane. At least the head portion and the throat portion of the frame are formed at least in part of a fiber composite material. When the racquet is tested under the racquet lateral bending test, the racquet has a lateral deflection of at least 6.0 mm when measured in a direction that is parallel to the string bed plane and perpendicular to the longitudinal axis. When the racquet is tested under the racquet torsional stability test, the racquet has an angular deflection of less than 5.5 degrees about the longitudinal axis. The head portion has a maximum beam height distance of at least 20 mm.

A bench top board scoring device is provided, having a frame having a first end and an opposite second end, a work area defined between the first and second ends, each end having at least one leg configured for contacting a substrate. A track is connected to the frame and extends between the first end and the second end, a carriage is slidably mounted to the track for travel between the first end and the second end, and an arm has an upper surface, a pivot end pivotally connected to the carriage, and an opposite knife mount end. A knife blade is mounted to the knife mount end. Additionally, the present device is constructed and arranged so that as the carriage is moved from the first end to the second end, wallboard samples placed in the work area and contacted by the knife blade receive a constant scoring force.

There is a method of making a tubular specimen with a predetermined wrinkle defect including providing a layup tool with a cavity forming member having a cavity which resembles a desired shape of the at least one wrinkle; orienting a composite material around the mandrel at a wrap angle to form a closed loop; positioning a wrinkle tool on the closed loop; and/or generating at least one wrinkle with a predetermined characteristic in a portion of the closed loop to form a tubular specimen. The predetermined characteristic is at least one of the following: wrinkle location, an outward wrinkle, an inward wrinkle, a wrinkle width, a wrinkle height, and a wrinkle length. In another aspect, there is a method of offset load testing a tubular composite specimen. In a third aspect, there is a method of determining allowable defects for a composite component.

In a first aspect, there is a method of making a specimen with a predetermined wrinkle defect, the steps including orienting a composite material around a layup tool at a wrap angle to form a closed loop; and generating at least one wrinkle with a predetermined characteristic in a portion of the closed loop to form a specimen. The predetermined characteristic is at least one of the following: wrinkle location, an outward wrinkle, an inward wrinkle, a wrinkle width, a wrinkle height, and a wrinkle length. In another aspect, there is a method of determining allowable defects for a composite component.

A coating bond test method includes, attaching with an adhesive a pull-off bar to a coating on a planar surface of a substrate for which a normal bond strength between the coating and the substrate is sought, reducing a first area defined by an interface between the substrate and the coating to a value less than a second area defined by an interface between the adhesive and the coating, urging the pull-off bar away from the substrate in a direction normal to the planar surface until failure occurs, and recording a load at which failure occurred.

A bench top board scoring device is provided, including a frame having a first end and an opposite second end, a work area defined between the first and second ends, each end having at least one leg configured for contacting a substrate. A track is connected to the frame and extends between the first end and the second end, a carriage is slidably mounted to the track for travel between the first end and the second end, and an arm has an upper surface, a pivot end pivotally connected to the carriage, and an opposite knife mount end. A knife blade is mounted to the knife mount end. Wherein the present device is constructed and arranged so that as the carriage is moved from the first end to the second end, wallboard samples placed in the work area and contacted by the knife blade receive a constant scoring force.

Wood-fiber insulation board is pressed to a uniform thickness and continuously advanced in a horizontal travel direction on a conveyor prior to subdivision into individual panels. The strength of the wood-fiber insulation board is determined by first pressing with an actuator a contact element downward at an actual pressure on a subregion of the advancing wood-fiber insulation board so as produce an actual deformation of the wood-fiber insulation board of between 1% to 7% of its thickness. Then a force sensor determines the actual pressure applied by the contact element to the board that produces the actual deformation and this the determined pressure and the actual deformation are transmitted to a central processor that extrapolates to a standardized deformation based on the determined pressure and actual deformation.

Fabrication of ballistic resistant fibrous composites having improved ballistic resistance properties. More particularly, ballistic resistant fibrous composites having enhanced a dynamic storage modulus, which correlates to low composite backface signature.

A rig for testing mode II fatigue of a composite component. The rig includes a clamp for clamping one end of the component. A first contact arrangement is provided for contacting one side of the component and a second contact arrangement is provided for contacting an opposing side of the component, the first and second contact arrangements being spaced from the clamp. A loading fork is provided for applying load to the component. The loading fork includes a first and a second portion arranged such that in use, when the loading fork is loading the component in one direction the first portion contacts the first contact arrangement and the second portion is spaced from the second contact arrangement, and when the loading fork is loading the component in an opposite direction the first portion is spaced from the first contact arrangement and the second portion contacts the second contact arrangement.