Safety State Evaluation Method Based on Attribute Recognition Model for Ancient Timber Buildings

Table 2

Safety grade classification for wood beam, Fang, and purlin.

Safety grade	Evaluation indexes
	Decadent	Insect attack	Cracks	Deflection	Lateral bending
		No insect holes along the length, no hollowing sounds while knocking
		No obvious insect holes along the length, no hollowing sounds while knocking
		Has obvious insect holes along the length, no hollowing sounds while knocking
		Has obvious insect holes along the length, hollowing sounds are heard while knocking

is the percentage of decayed area of cross section. is the sinusoidal value of angle between crack and longitudinal direction. is the calculation span of beam, purlin, and Fang.