8578
This test consists of DCB specimen fabricated from using unidirectional FFF layers , an 8 μm Kapton starter crack inserted in the midplane during the printing process , and reinforcing glass/epoxy doublers to prevent DCB arm failure during loading .
 fabricated, unidirectional, FFF, midplane, printing process, failure
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
Answer:
 fabricated, unidirectional, FFF, midplane, printing process, failure