tailieunhanh - APA Engineered Wodd Handbooks Episode 1

Tham khảo tài liệu 'apa engineered wodd handbooks episode 1', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | CHAPTER ONE INTRODUCTION TO WOOD AS AN ENGINEERING MATERIAL Steven Zylkowski Director Engineered Wood Systems BASIC STRUCTURE OF WOOD The unique characteristics and abundant supply of wood have made it the most desirable building material throughout history. Manufacturing technologies based on the modern understanding of wood have led to a family of engineered wood products that optimize properties to meet the specific needs of design professionals. While there are many types of technically advanced wood products such as machine stress-rated MSR lumber and metal-plated connected wood trusses that are considered to be part of the broad definition of engineered wood products they have not been included in this Handbook. Information on these and other non-glued wood products may be found in other manuals and literature sources. For the purposes of this Handbook engineered wood products are defined as products manufactured from various forms of wood fiber bonded together with water-resistant adhesives. Engineered wood products are intended for structural applications and include such products as structural plywood oriented strand board OSB glued-laminated timber laminated veneer lumber LVL and wood I-joists. These products are also known as wood composites. As an organic material derived from trees wood has a cellular structure composed of longitudinally arranged fibers. This directional aspect of wood imparts directional properties that are well recognized by wood engineers and manufacturers of wood products. While the properties of engineered wood products are largely determined by manufacturing processes that change the configuration of the wood fibers basic wood characteristics are primary to the end product. Wood characteristics are determined by many factors such as species growing conditions and wood quality. Softwoods and Hardwoods One fundamental characterization of wood is based upon whether the wood is from a hardwood or softwood tree.