Research On Wrist Structure Design And Kinematic Analysis And Simulation Of NC Fiber Placement Machine

In the aerospace, national defense and kinds of civil fields, advanced compositematerials are getting more and more widely applied for its excellent overallperformance compared to traditional materials.Fiber placement technology is developed on the basis of fiber winding technology,using placement head instead of winding head, it solves the problem that the fiberwinding technology can’t wind on the concave surface, and make the parts localthickening. fiber placement technology inherits the advantages of fiber windingmachine and tape placement machine, it can better accommodate component toplacement. Fiber placement machine can automatically realize placement trajectoryfrom the trajectory planning under control. Because it can placement fiber by variableangle, change the fiber to placement width and placement fiber on the concave, it isvery suitable for surface of the non-gyro body with a relatively complex shape.Fiber placement machine with seven degrees of freedom of this research projectconsists of two sliding pairs, five revolute pairs and placement head. Compared to aoriginal fiber placement machine of the laboratory, it uses a revolute pair instead of theY-axis sliding pair, and design the structure of the wrist component. The wristcomponent is an important part of the the fiber placement machine,one end of it connectto the outrigger of the machine, the other end to the placement head, the wrist plays amajor role in the adjustment of the placement head posture, which determines the rangeof motion of the placement head. Structure, movement and the mechanical properties ofthe wrist component are the main objects of study in this paper.The kinematic analysis is the basis of static analysis,dynamic analysis, workspaceanalysis, and controlling the placement trajectory to achieve, an indispensable link ofresearching motion and the mechanical properties of the wrist or the fiber placementmachine.Fiber placement movement is composition of motion to contact point on thepressure roller of placement head and rotary movement of the mandrel. Consequentlyfor convenience the motion of placement machine was broken down into twoparts,including the mechanical arm and the mandrel, to avoid the problem of redundantmechanism kinematics.And then D-H method can be used to research the kinematicanalysis of the arm part, get its kinematic equations to calculate the forward and inversesolutions;and build the Jacobian matrix of the arm part directly through vector productmethod.Kinematics simulation basing on CATIA and dynamics simulation on ADAMS ofthe fiber placement machine, focuses on analysis of the simulation results of the wristpart to verify the movement and the mechanical properties of it.Verify the reasonableness of choosing servo motor, and check the strength and stiffness of the keycomponent of the wrist part through ABAQUS finite element analysis basing on theresults of dynamics simulation to prove the rationality of the structural parameters.