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PEER-REVIEWED ARTICLE
Materials A total of 194 pieces of full-size WCPs were used in this study. There were 67 pieces of PB panels with different nominal thicknesses of 9, 16, 18, and 25 mm; 69 pieces of MDF panels with nominal thicknesses of 9, 12, 15, and 18 mm; and 58 pieces of PW panels with nominal thicknesses of 9, 15, 18, and 25 mm. The MDF panels were provided by a local MDF manufacturer (Krono, Beijing, China). These panels were manufactured from mixed species of both softwood and hardwood using urea-formaldehyde resin. The PB and PW panels were purchased from the local supplier (Beijing, China). So the resin types or other manufacturing characteristics were not available for this test. The PW panels were made from poplar veneer. Table 1 shows the specifications of the full-size WCP samples. The length ( L ), width ( b ), and thickness ( h ) of the panels were measured prior to testing. Average density of the panels was calculated based on the weight and volume. The moisture contents of the panels were determined using the National Standards of the People’s Republic of China GB/T 17657 -2013 (2013). Table 1. Dimensions and Physical Characteristics for the Full-size Wood Composite Panels Tested
Average Density (kg/m 3 )
Average Panel Sizes (mm)
Panel Code
Quantity (Panels)
Average Moisture Content (%)
Thickness
Width
Length 2442.2 2441.0 2437.0 2439.2 2446.6 2444.2 2445.8 2443.8 2438.1 2439.4 2438.5 2439.5
PB9
13 25 24
9.01
1222.9 1223.1 1220.2 1219.8 1222.0 1221.6 1222.0 1221.4 1219.1 1220.9 1221.0 1219.2
658 699 655 672 771 827 882 773 505 503 522 528
4.5 4.3 5.7 6.8 4.5 3.9 4.0 3.9 9.4
PB16 PB18 PB25 MDF9
16.04 18.03 25.19
5 5
9.01
MDF12 MDF15 MDF18
20 20 24 15 15 15 13
12.03 15.07 18.03
PW9
9.42
PW15 PW18 PW25
14.48 17.01 24.37
10.5
8.6 9.8
After conducting the full size vibration test (described below), the measured panels were cut into smaller specimens for the cantilever beam vibration test. One specimen was cut from each full-size WCP along the length of the panel. As for the dimensions of the specimen, to ensure the effects of shear force and rotary motion in the specimen could be neglected, the ratio of free length to thickness were greater than 14.5 (Hunt et al. 2013). Detailed dimensions are shown in Table 2. The moisture content has a strong influence on material properties. Unfortunately, a laboratory with constant climate could not be used for the tests. To limit the influence of moisture content on comparison test results, there was a minimal time difference between the full-size tests and cantilever beam tests. The interval between the two tests was a maximum of 2 h for cutting specimens for the cantilever beam vibration test from the panel immediately after testing the full-size panel. The two tests, the full-size panel and the smaller cantilever beam test, were conducted in a room with a relative humidity of 30 f 5% and a temperature of 20 f 2 q C.
4596
Guan et al . (2016). “Dynamic viscoelasticity,” B io R esources 11(2), 4593-4604.
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