Abstract: A method for detecting and responding to damage in a rotor blade of a wind turbine includes monitoring at least one signal of a pitch actuator of a pitch system of the rotor blade of the wind turbine. The signal(s) is a proxy for a pitch driving torque of the pitch actuator of the pitch system. Thus, the method includes defining a metric that captures certain behavior of the proxy for the pitch driving torque of the pitch actuator of the pitch system. The method further includes comparing the metric to a corresponding metric associated with a reference rotor blade representing a healthy rotor blade. Moreover, the method includes implementing a control action when the metric is outside of a predetermined range defined by the healthy rotor blade.

Abstract: A method for producing a hollow composite structure, such as a spar beam for use in a wind turbine blade, includes placing fiber reinforcement material around a mandrel within a mold, and curing the fiber reinforcement material. The mandrel is formed from a compressible material having a rigid neutral state with a rigidity to maintain a defined shape of the mandrel during lay up and curing of the fiber reinforcement material. Subsequent to curing, a vacuum is drawn on the mandrel to compress the compressible material so that the compressed mandrel can be drawn out through an opening in the composite structure, the opening having a size such that the mandrel could not be withdrawn through the opening in the rigid neutral state of the mandrel.

Abstract: A method for detecting and reducing edgewise vibrations in a rotor blade of a wind turbine includes, for a given wind speed, determining a frequency or frequency band at which edgewise vibrations are producible in the rotor blade. The method determines an electrical characteristic of the pitch actuator that correlates to an increased torque required to hold a pitch angle of the rotor blade constant at the frequency or frequency band. During an operational power-production mode of the wind turbine, the electrical characteristic of the pitch actuator is monitored. Upon the electrical characteristic reaching a predefined limit value indicative of edgewise vibrations in the rotor blade, corrective action is initiated by the wind turbine controller to reduce or prevent the edgewise vibrations.

Abstract: A rotor blade for a wind turbine includes first and second blade segments extending in opposite directions from a chord-wise joint. Each of the first and second blade segments has at least one shell member defining an airfoil surface and an internal support structure. The first blade segment includes a beam structure extending lengthwise that structurally connects with the second blade segment at a receiving section. At least one of the internal support structures of the first and second blade segments includes at least one spar cap. The rotor blade also includes one or more pin joints positioned on the spar cap(s) for connecting the blade segments. The spar cap is constructed of varying forms of materials along a span of the rotor blade, including at least two of: one or more infused composite laminates, one or more pre-preg composite laminates, one or more pre-fabricated or pre-cured composite elements, one or more additively-manufactured structures, or one or more non-composite structural solids.

Abstract: A jointed rotor blade includes a first blade segment and a second blade segment extending in opposite directions from a chord-wise joint. Each of blade segments has at least one shell member defining an airfoil surface and an internal support structure. The internal support structure of the first blade segment includes a beam structure extending lengthwise that structurally connects with the internal support structure of the second blade segment via a receiving section. The rotor blade further includes one or more pin joints positioned on at least one of internal support structures of the first blade segment or the second blade segment. Thus, at least one of internal support structures of the first blade segment or the second blade segment includes varying material combinations along a span of the rotor blade at locations of the one or more pin joints so as to reinforce the one or more pin joints.

Abstract: The present disclosure is directed to a method for forming a wind turbine rotor blade. The method includes placing first and second prefabricated skin panels defining a portion of a root section of the wind turbine rotor blade, a pressure side of the wind turbine rotor blade, or a suction side of the wind turbine rotor blade in a mold. The first and second prefabricated skin panels partially overlap to define a connection region. A vacuum bag is placed over the mold. The connection region is infused with a resin.

Abstract: A rotor blade for a wind turbine includes first and second blade segments extending in opposite directions from a chord-wise joint. Each of the first and second blade segments has at least one shell member defining an airfoil surface and an internal support structure. The first blade segment includes a beam structure extending lengthwise that structurally connects with the second blade segment at a receiving section. At least one of the internal support structures of the first and second blade segments includes at least one spar cap. The rotor blade also includes one or more pin joints positioned on the spar cap(s) for connecting the blade segments. The spar cap is constructed of varying forms of materials along a span of the rotor blade, including at least two of: one or more infused composite laminates, one or more pre-preg composite laminates, one or more pre-fabricated or pre-cured composite elements, one or more additively-manufactured structures, or one or more non-composite structural solids.

Abstract: A method for producing a hollow composite structure, such as a spar beam for use in a wind turbine blade, includes placing fiber reinforcement material around a mandrel within a mold, and curing the fiber reinforcement material. The mandrel is formed from a compressible material having a rigid neutral state with a rigidity to maintain a defined shape of the mandrel during lay up and curing of the fiber reinforcement material. Subsequent to curing, a vacuum is drawn on the mandrel to compress the compressible material so that the compressed mandrel can be drawn out through an opening in the composite structure, the opening having a size such that the mandrel could not be withdrawn through the opening in the rigid neutral state of the mandrel.

Abstract: A jointed rotor blade includes a first blade segment and a second blade segment extending in opposite directions from a chord-wise joint. Each of blade segments has at least one shell member defining an airfoil surface and an internal support structure. The internal support structure of the first blade segment includes a beam structure extending lengthwise that structurally connects with the internal support structure of the second blade segment via a receiving section. The rotor blade further includes one or more pin joints positioned on at least one of internal support structures of the first blade segment or the second blade segment. Thus, at least one of internal support structures of the first blade segment or the second blade segment includes varying material combinations along a span of the rotor blade at locations of the one or more pin joints so as to reinforce the one or more pin joints.

Abstract: Systems and methods for joining blade components of a rotor blade are provided. A method includes positioning a first blade component and a second blade component such that a joint location of the first blade component and a joint location of the second blade component are proximate each other. The method further includes applying a force to an outer surface of the second blade component and an opposing force to an inner surface of the second blade component. The force and opposing force maintain an aerodynamic contour of the second blade component. The method further includes connecting the joint location of the first blade component and the joint location of the second blade component together.

Abstract: The present disclosure is directed methods for modifying molds of rotor blades of a wind turbine. In certain embodiments, the blade mold is constructed, at least in part, of a thermoplastic material optionally reinforced with a fiber material. In one embodiment, the method includes identifying at least one blade mold addition for the mold of the rotor blade and positioning the blade mold addition at a predetermined location of the mold of the rotor blade. Further, the blade mold addition is constructed, at least in part, of a thermoplastic material. Thus, the method includes applying at least one of heat, pressure, or one or more chemicals at an interface of the blade mold addition and the mold so as to join the blade mold addition to the mold. In further embodiments, the methods described herein are also directed repairing thermoplastic blade molds.

Abstract: The present disclosure is directed to a modular rotor blade constructed of thermoset and/or thermoplastic materials for a wind turbine and methods of assembling same. The rotor blade includes a pre-formed main blade structure constructed, at least in part, from a thermoset material. The rotor blade also includes at least one blade segment configured with the main blade structure. The blade segment(s) is constructed, at least in part, of a thermoplastic material reinforced with at least one fiber material.

Abstract: A rotor blade assembly for a wind turbine may include a first blade segment having a first joint end and a second blade segment having a second joint end, with the blade segments being coupled together such that the first and second joint ends are located at or adjacent to a joint interface between the blade segments. The blade assembly may also include a pre-loaded beam extending outwardly from the second blade segment across the joint interface such that the pre-loaded beam is received within the first blade segment. The pre-loaded beam may be compressed between the opposed internal structural components of the first blade segment such that a first engagement interface is defined between a first side of the pre-loaded beam and the first internal structural component and a second engagement interface is defined between an opposed second side of the pre-loaded beam and the second internal structural component.

Abstract: A jointed rotor blade assembly may include a first blade segment having a first outer shell terminating at a first joint end and a second blade segment coupled to the first blade segment at a blade joint. The second blade segment may include a second outer shell terminating at a second joint end. The outer shells may overlap one another at the blade joint such that an overlapping region is defined between the first and second joint ends. In addition, the first outer shell may be spaced apart from the second outer shell along at least a portion of the overlapping region such that a gap is defined between the outer shells within the overlapping region. Moreover, the rotor blade assembly may include a sealing member positioned between the outer shells within the overlapping region that is configured to allow relative movement between the outer shells at the blade joint.

Abstract: The present disclosure is directed methods for manufacturing spar caps for wind turbine rotor blades. In certain embodiments, the method includes forming an outer frame of the spar cap via at least one of three-dimensional (3D) pultrusion, thermoforming, or 3D printing. As such, the outer frame has a varying cross-section that corresponds to a varying cross-section of the rotor blade along a span thereof. The method also includes arranging a plurality of structural materials (e.g. layers of pultruded plates) within the pultruded outer frame of the spar cap and infusing the structural materials and the outer frame together via a resin material so as to form the spar cap. The resulting spar cap can then be easily incorporated into conventional rotor blade manufacturing processes and/or welded or bonded to an existing rotor blade.

Abstract: The present disclosure is directed to a method for manufacturing a blade component for a rotor blade of a wind turbine. The method includes arranging a fiber material in a mold of the blade component. The method also includes placing at least one pre-cured laminate material atop the fiber material. Another step includes infusing the fiber material and the pre-cured laminate material together via a resin material so as to form the blade component. The method also includes allowing the blade component to cure, the pre-cured laminate material forming at least a portion of an outer surface of the blade component.

Abstract: The present disclosure is directed to methods for joining rotor blade components using thermoplastic welding.

Abstract: The present subject matter is directed to a rotor blade assembly for a wind turbine having an improved shear web configuration. The rotor blade assembly includes an upper shell member having a spar cap configured on an internal surface thereof and a lower shell member having a spar cap configured on an internal surface thereof. The shear web extends between the spar caps along a longitudinal length of the blade. Further, the shear web includes at least one pultruded component defining a hollow cross-section.

Abstract: A joint assembly for a wind turbine rotor blade includes a male structural member extending longitudinally through female structural members configured with a plurality of rotor blade segments. The female structural member includes first bore holes on opposing sides thereof that are aligned in a chord-wise direction. The male structural member includes second bore holes on opposing sides thereof that are aligned with the first bore holes. At least one chord-wise extending gap is defined between an outer side surface of the male structural member and an inner side surface of the female structural member. A chord-wise extending pin extends through the first and second bore holes to join the male and female structural members. At least one flanged bushing is arranged in the first and second bore holes such that a flange of the bushing extends within the chord-wise extending gap.

Abstract: A joint assembly for joining rotor blade segments of a wind turbine rotor blade includes a female structural member secured within a first rotor blade segment. The female structural member includes first bore holes on opposing sides thereof that are aligned in a chord-wise direction. Further, the joint assembly includes a male structural member extending longitudinally from an end face of a second rotor blade segment. As such, the male structural member is received within the female structural member of the first rotor blade segment such that the first and second rotor blade segments are aligned and connected. The male structural member includes second bore holes on opposing sides thereof. Further, the second bore holes are aligned with the first bore holes. Moreover, the joint assembly includes at least one chord-wise extending pin extending through the first and second bore holes so as to join the first and second rotor blade segments.