System for additively manufacturing composite structures

Abstract

A system is disclosed for additively manufacturing a composite structure. The system may include a support, and a print head connected to and moveable by the support. The system may also include an encoder configured to generate a signal indicative of an amount of material passing through the print head, and a controller in communication with the encoder. The controller may be configured to selectively implement a corrective action in response to the signal.

What is claimed is: 
     
         1 . A method of additively manufacturing a composite structure, comprising:
 wetting a continuous reinforcement with a matrix inside a print head to form a composite material;   discharging from the print head the composite material;   moving the print head during discharging of the composite material;   generating a signal indicative of a first amount of the composite material discharged from the print head;   determining a second amount of the composite material expected to be discharged from the print head; and   selectively implementing a corrective action based at least in part on a difference between the first and second amounts.   
     
     
         2 . The method of  claim 1 , further including determining a travel distance of the print head, wherein determining the second amount of the composite material includes determining the second amount of the composite material based at least in part on the travel distance of the print head. 
     
     
         3 . The method of  claim 2 , further including determining that least one of untacking or breakage of the composite material has occurred based at least in part on the first amount of the composite material being less than the second amount of the composite material. 
     
     
         4 . The method of  claim 2 , further including:
 attempting to sever the composite material discharging from the print head; and   determining that severing of the composite material has failed based at least in part on the first amount of the composite material being greater than the second amount of the composite material.   
     
     
         5 . The method of  claim 4 , wherein selectively implementing the corrective action includes attempting an additional severing operation to sever the composite material. 
     
     
         6 . The method of  claim 1 , wherein selectively implementing the corrective action includes at least one of generating a flag indicating a potential malfunction, pausing of a current printing operation, or cancelling the current printing operation. 
     
     
         7 . The method of  claim 1 , further including exposing the composite material discharging from the print head to a cure energy. 
     
     
         8 . The method of  claim 1 , further including directing the composite material from a supply to the print head, wherein the signal is associated with the supply. 
     
     
         9 . The method of  claim 1 , further including passing the composite material through a feeder to a nozzle of the print head, wherein the signal is associated with the feeder. 
     
     
         10 . The method of  claim 1 , further including:
 receiving an indication of a tacking operation in which the composite material is secured to a surface; and   determining, based at least in part on the indication, that the second amount of the composite material is greater than zero.   
     
     
         11 . A method for additively manufacturing a composite structure, comprising:
 discharging from a print head a composite material, including a continuous reinforcement at least partially coated with a matrix;   moving the print head during discharging of the composite material;   generating a signal indicative of an amount of the composite material discharging from the print head during movement of the print head;   determining a movement distance of the print head during discharging; and   selectively implementing a corrective action based at least in part on the movement distance and the amount of the composite material.   
     
     
         12 . The method of  claim 11 , wherein, when the amount of the composite material passing through the print head is less than the movement distance of the print head, the method further includes determining that at least one of untacking or breakage of the continuous reinforcement has occurred. 
     
     
         13 . The method of  claim 12 , wherein selectively implementing the corrective action includes at least one of:
 generating a flag indicating that a malfunction has occurred;   pausing of a current printing operation; or   cancelling of the current printing operation.   
     
     
         14 . The method of  claim 11 , further including severing the composite material passing through the print head, wherein when the amount of the composite material passing through the print head is greater than the movement distance of the print head, the method further includes determining that the severing of the composite material has failed. 
     
     
         15 . The method of  claim 14 , wherein selectively implementing the corrective action includes attempting an additional severing of the composite material. 
     
     
         16 . The method of  claim 11 , wherein:
 the amount of the composite material is zero based on implementation of a severing operation; and   the amount of the composite material expected to be passing through the print head is greater than zero based on implementation of a tacking operation.   
     
     
         17 . The method of  claim 11 , further including wetting the continuous reinforcement with the matrix at a wetting location inside the print head, wherein generating the signal includes detecting the amount between the wetting location and a supply of the continuous reinforcement. 
     
     
         18 . A method of additively manufacturing a composite structure, comprising:
 discharging from a print head a composite material, including a continuous reinforcement at least partially coated with a matrix;   determining an amount of the composite material being pulled through the print head during discharging;   moving the print head during discharging of the composite material;   determining a travel distance of the print head; and   selectively implementing a corrective action based on a difference between the amount of the composite material and the travel distance.   
     
     
         19 . The method of  claim 18 , wherein, when the amount of the composite material passing through the print head is less than the travel distance of the print head, the corrective action includes at least one of generating a flag indicating that at least one of untacking or continuous reinforcement breakage may have occurred. 
     
     
         20 . The method of  claim 18 , further including selectively severing the continuous reinforcement, wherein when the amount of the composite material passing through the print head is greater than the travel distance of the print head, the corrective action includes attempting to sever the continuous reinforcement again.