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The Preparation And Manufacture Performance Research Of Metal Net-Lvl Composite

Posted on:2013-05-07Degree:MasterType:Thesis
Country:ChinaCandidate:J LiFull Text:PDF
GTID:2231330374972991Subject:Wood science and technology
Abstract/Summary:PDF Full Text Request
The paper mainly discussed the enhancement of the laminated veneer lumber (LVL) with monolayer metal net and multilayer metal net, the factors selected and process optimization were included in the content. The most suitable nondestructive testing method for the metal net-LVL composite was determined through the correlation between the dynamic performance and static performance.In the paper, it was found that the bondline properties between metal net and wood veneer had significant influence on the properties of LVL. The effect of compression ratio on the mechanical properties of metal net-LVL composite was studied through the one time compressing and the two times compressing; the results showed that the compressing ratio had obvious influences on the performance enhancement of metal net-LVL composite. The reasons of compressing ratio improving the properties of LVL were that the density of LVL changed due to the change of compress ratio and the bondline strength between metal net and wood veneers was improved. With the method of one time compressing, a better properties of metal net-LVL composite was obtained when the whole compressing ratio was31%, with the two times compressing, the bondline strength between metal net and wood veneers was improved slightly.The optimization process of monolayer metal net-LVL composite was determined by orthogonal and single-factor experiments were as follow:15°of metal net,25%of compressing ratio,2.0%of coupling agent and the metal length was half of the sample length. Under this condition, the MOE and MOR of monolayer metal net-LVL composite increased36.34%and27.47%respectively through the comparison of the control samples.The optimization process of multilayer metal net-LVL composite was determined on the basis of the optimization process of monolayer metal net-LVL composite. The best mechanical property was obtained when the LVL enhanced with two layers metal net and the metal nets were located in the first and second intervals between the veneers which were on the underside of the sample. Comparing with the control samples, the MOE and MOR of LVL increased49.49%and25%respectively when it was under the condition above.In this study, the dynamic properties of the metal net-LVL composite were obtained by using four different nondestructive testing (NDT) methods, including surface wave propagation method, longitudinal transmission method, longitudinal vibration method and flexural vibration method, the values of static properties were also obtained by using the static bending test.The correlativity was investigated between the dynamic and static properties, and there was a best correlation between the dynamic properties and static properties through out-plane flexural vibration method. So the out-plane vibration can be as a kind of nondestructive test for the metal net-LVL composite.
Keywords/Search Tags:Metal Net, Laminated Veneer Lumber, Compressing Ratio, NondestructiveTesting
PDF Full Text Request
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