We implemented the process of producing a new Rib in three different ways, and we selected the process that was the most affordable and required the least labor, and we did it. This paper also considers the influence ...We implemented the process of producing a new Rib in three different ways, and we selected the process that was the most affordable and required the least labor, and we did it. This paper also considers the influence of the cost of the form from MDF, Alumina and Steel on the quality of the product.展开更多
We studied the effects of nanoparticles of organo-silane（NOS） compounds in the size range of20–80 nm on physical and mechanical properties in medium density fiberboard,and used NOS at four consumption levels of 0,5...We studied the effects of nanoparticles of organo-silane（NOS） compounds in the size range of20–80 nm on physical and mechanical properties in medium density fiberboard,and used NOS at four consumption levels of 0,50,100,and 150 g kg-1dry wood fibers.Density of all treatments was kept constant at 0.67 g cm-3.The water-repellent property of organo-silane significantly reduced water absorption（WA） and thickness swelling but mechanical properties declined due to the reduced proportion of wood-fiber as organo-silane was added to the matrix：the compression ratio of MDF panels and the integrity among wood-fibers both declined,resulting in reduced mechanical properties.We recommend use of 50 g of NOS/kg wood-fiber to improve WA and thickness swelling while retaining acceptable mechanical properties.展开更多
Medium density fiberboard (MDF) is a highly competitive wooden material especially in office furniture industry. Damage and failure occur frequently in MDF due to low mechanical properties. In the present work, a modi...Medium density fiberboard (MDF) is a highly competitive wooden material especially in office furniture industry. Damage and failure occur frequently in MDF due to low mechanical properties. In the present work, a modification was performed to enhance fracture properties of MDF. The MDF plate/core was inserted into two layers (face sheet) of glass fiber composite laminates using hand layup technique. Face sheet/core delamination involves the separation of a face sheet from the core material in a sandwich MDF. Therefore, delamination test using double cantilever beam (DCB) specimen was carried out. The test measured the debonding fracture toughness (GIC) or separation strength between face sheet material (glass fiber/epoxy laminates) with MDF core material. The test is based on compliance strategy measuring fracture toughness (GIC). It was found that the fracture toughness was increased. Extended finite element model (XFEM) based on virtual crack closer technique (VCCT) was constructed to simulate the delamination behaviors of face sheet/core materials. The model results were in good agreement with the experimental ones.展开更多
中密度纤维板(Medium Density Fiberboard,MDF)作为木材综合利用率高的一种人造板材,其厚度精度决定了板材的力学性能,从而影响其质量。本文将连续热压机电液位置伺服系统作为被控对象,针对MDF板坯厚度控制问题,提出一种带高增益观测器...中密度纤维板(Medium Density Fiberboard,MDF)作为木材综合利用率高的一种人造板材,其厚度精度决定了板材的力学性能,从而影响其质量。本文将连续热压机电液位置伺服系统作为被控对象,针对MDF板坯厚度控制问题,提出一种带高增益观测器的滑模控制策略。首先通过设计高增益观测器对系统输出的位置信号进行观测,将位置、速度及加速度信号的估计值返回滑模控制器,实现了无需速度、加速度测量的滑模控制,保证了观测误差一致最终有界。然后通过构造合适的Lyapunov函数,证明了所提出的控制策略不但能使系统指数渐近稳定,而且保证了跟踪误差的一致最终有界性。仿真实验结果表明,所提出的控制方法可以保证系统精准快速地跟踪位置信号,从而可以保证MDF获得良好的厚度精度。展开更多
Of considerable importance and a principal goal in business is the creation of customer satisfaction. Evalu- ation of end user preferences for producers of particleboard and medium density fiberboard （MDF） requires ...Of considerable importance and a principal goal in business is the creation of customer satisfaction. Evalu- ation of end user preferences for producers of particleboard and medium density fiberboard （MDF） requires indices for the assessment of markets and modification of product quality. However, only sporadic research has been carried out in this field. Therefore, the goal of this survey was to identify indices with respect to the points of view of： 1） consumers in order to select particleboard and MDF, 2） suppliers in order to consider production strategies, improve product quality, improve competitive ability of domestic producers in the market and help industry to be more customer oriented. This survey consisted of two stages. In the first stage, factors affecting customer preferences in the selection of particleboard and MDF were determined using a Delphi method, with the help of experts and a group of principal users of these prod- ucts. Then these factors were categorized in three groups： qualitative, technical and technological and marketing factors. Furthermore, questionnaires were prepared and distributed among consumers and responses evaluated and weighted by using an analytic hierarchy process （AHP） using expert choice software. Our results show that at both stages, the consistency ratio was less than 0.1, indicating that all results and judgments were stable and acceptable. The results obtained from questionnaires about particleboard rank the priorities for factors in the selection by consumers as follows： nail and screw holding ability, homogeneity in structure, edge strength of panel, durability and bending strength. The most important factors for MDF were machinability of panels, homogeneity in structure, nail and screw holding ability, edge strength of panel, durability and bending strength.展开更多
针对中密度纤维板MDF(Medium Density Fiberboard)连续平压机保压段板坯厚度控制问题,提出一种反步控制策略:对MDF连续平压位置伺服系统进行位置跟踪控制,采用Lyapunov稳定性理论保证跟踪误差渐近收敛于零。所设计的控制器有效地解决常...针对中密度纤维板MDF(Medium Density Fiberboard)连续平压机保压段板坯厚度控制问题,提出一种反步控制策略:对MDF连续平压位置伺服系统进行位置跟踪控制,采用Lyapunov稳定性理论保证跟踪误差渐近收敛于零。所设计的控制器有效地解决常规PID控制存在的超调、收敛速度慢和跟踪误差大等问题。在Matlab2009a环境下进行仿真,仿真结果表明:采用反步法设计的控制器能实现系统快速准确的位置跟踪,与常规PID控制器相比较,该控制器具有收敛速度快、跟踪精度高和跟踪误差小等优点。展开更多
文摘We implemented the process of producing a new Rib in three different ways, and we selected the process that was the most affordable and required the least labor, and we did it. This paper also considers the influence of the cost of the form from MDF, Alumina and Steel on the quality of the product.
基金conducted as a joint research projectfinanced by SRTTU(Iran)UPM(Malaysia)
文摘We studied the effects of nanoparticles of organo-silane（NOS） compounds in the size range of20–80 nm on physical and mechanical properties in medium density fiberboard,and used NOS at four consumption levels of 0,50,100,and 150 g kg-1dry wood fibers.Density of all treatments was kept constant at 0.67 g cm-3.The water-repellent property of organo-silane significantly reduced water absorption（WA） and thickness swelling but mechanical properties declined due to the reduced proportion of wood-fiber as organo-silane was added to the matrix：the compression ratio of MDF panels and the integrity among wood-fibers both declined,resulting in reduced mechanical properties.We recommend use of 50 g of NOS/kg wood-fiber to improve WA and thickness swelling while retaining acceptable mechanical properties.
文摘Medium density fiberboard (MDF) is a highly competitive wooden material especially in office furniture industry. Damage and failure occur frequently in MDF due to low mechanical properties. In the present work, a modification was performed to enhance fracture properties of MDF. The MDF plate/core was inserted into two layers (face sheet) of glass fiber composite laminates using hand layup technique. Face sheet/core delamination involves the separation of a face sheet from the core material in a sandwich MDF. Therefore, delamination test using double cantilever beam (DCB) specimen was carried out. The test measured the debonding fracture toughness (GIC) or separation strength between face sheet material (glass fiber/epoxy laminates) with MDF core material. The test is based on compliance strategy measuring fracture toughness (GIC). It was found that the fracture toughness was increased. Extended finite element model (XFEM) based on virtual crack closer technique (VCCT) was constructed to simulate the delamination behaviors of face sheet/core materials. The model results were in good agreement with the experimental ones.
文摘中密度纤维板(Medium Density Fiberboard,MDF)作为木材综合利用率高的一种人造板材,其厚度精度决定了板材的力学性能,从而影响其质量。本文将连续热压机电液位置伺服系统作为被控对象,针对MDF板坯厚度控制问题,提出一种带高增益观测器的滑模控制策略。首先通过设计高增益观测器对系统输出的位置信号进行观测,将位置、速度及加速度信号的估计值返回滑模控制器,实现了无需速度、加速度测量的滑模控制,保证了观测误差一致最终有界。然后通过构造合适的Lyapunov函数,证明了所提出的控制策略不但能使系统指数渐近稳定,而且保证了跟踪误差的一致最终有界性。仿真实验结果表明,所提出的控制方法可以保证系统精准快速地跟踪位置信号,从而可以保证MDF获得良好的厚度精度。
文摘Of considerable importance and a principal goal in business is the creation of customer satisfaction. Evalu- ation of end user preferences for producers of particleboard and medium density fiberboard （MDF） requires indices for the assessment of markets and modification of product quality. However, only sporadic research has been carried out in this field. Therefore, the goal of this survey was to identify indices with respect to the points of view of： 1） consumers in order to select particleboard and MDF, 2） suppliers in order to consider production strategies, improve product quality, improve competitive ability of domestic producers in the market and help industry to be more customer oriented. This survey consisted of two stages. In the first stage, factors affecting customer preferences in the selection of particleboard and MDF were determined using a Delphi method, with the help of experts and a group of principal users of these prod- ucts. Then these factors were categorized in three groups： qualitative, technical and technological and marketing factors. Furthermore, questionnaires were prepared and distributed among consumers and responses evaluated and weighted by using an analytic hierarchy process （AHP） using expert choice software. Our results show that at both stages, the consistency ratio was less than 0.1, indicating that all results and judgments were stable and acceptable. The results obtained from questionnaires about particleboard rank the priorities for factors in the selection by consumers as follows： nail and screw holding ability, homogeneity in structure, edge strength of panel, durability and bending strength. The most important factors for MDF were machinability of panels, homogeneity in structure, nail and screw holding ability, edge strength of panel, durability and bending strength.
文摘针对中密度纤维板MDF(Medium Density Fiberboard)连续平压机保压段板坯厚度控制问题,提出一种反步控制策略:对MDF连续平压位置伺服系统进行位置跟踪控制,采用Lyapunov稳定性理论保证跟踪误差渐近收敛于零。所设计的控制器有效地解决常规PID控制存在的超调、收敛速度慢和跟踪误差大等问题。在Matlab2009a环境下进行仿真,仿真结果表明:采用反步法设计的控制器能实现系统快速准确的位置跟踪,与常规PID控制器相比较,该控制器具有收敛速度快、跟踪精度高和跟踪误差小等优点。
