Q2. What future works have the authors mentioned in the paper "Defect layer method to capture effect of gaps and overlaps in variable stiffness laminates made by automated fiber placement" ?
Future work is required to obtain a Pareto front that considers the effect of gaps or overlaps on the in-plane stiffness and the buckling load of the laminates. Furthermore, strength properties for a defect layer can be derived and used in a progressive damage simulation of variable stiffness laminates with gaps and/or overlap.
Q3. What is the effect of gaps on the in-plane stiffness of laminates?
strength properties for a defect layer can be derived and used in a progressive damage simulation of variable stiffness laminates with gaps and/or overlap.
Q4. What is the effect of gaps on the strength of laminates?
It was found that introducing gaps reduces the laminate strength [10], and the average strain [11], while the overlaps can cause an increase in strength of maximum 13% compared to a non-defective laminate [12], and 93% improvement in buckling load of a panel compared to a straight fiber case [13].
Q5. How can a variable stiffness laminate be designed?
A variable stiffness laminate can be designed by setting a reference fiber path and offsetting the subsequent fibers to cover the whole laminate.
Q6. What is the thickness of a gap-modified defect layer?
While the thickness of a gap-modified defect layer is that of a regular composite layer, the thickness of an overlap-modified defect layer increases proportionally with the overlap area percentage.
Q7. How much improvement is expected in the buckling load of laminates?
In other words, the emerging gaps in the laminate (gap area of 12.4%) reduce the buckling load improvement by 12.4%, which is about one third of the expected improvement in the buckling load.
Q8. How does the defect layer method affect the in-plane stiffness of laminates?
For the second laminate configuration, overlaps have been shown to improve the in-plane stiffness and buckling load by 11% and 71%, respectively.
Q9. How can the FE model of the variable stiffness laminates be generated?
Once the location of gaps or overlaps have been predicted through the MATLAB subroutines presented in Section 3.1, the FE model of the variable stiffness laminates can be generated in ANSYS.
Q10. What is the effect of gaps on the in-plane stiffness and buckling load?
As a result, gaps produced during the manufacturing process has the effect of reducing the benefit of fiber steering, whereas overlaps can increase the in-plane stiffness and the buckling load over the baseline by 11% and 71%, respectively.