GROUP-3

• Loading Unit - where the test specimen takes place and the load that must be exerted to the material.
• Load Frame - consists of table, upper and lower crosshead.
• Upper crosshead - to clamp the specimen
• Lower crosshead - movable crosshead
• Elongation Scale - the relative movement of the lower and upper table
• Control Unit - where the load is applied and get the corresponding test result.
• Hydraulic Power Unit - consists of an oil pump that provides non-pulsating oil flow into the main cylinder of the load unit.
• Load measuring unit - this unit has a pendulum dynamometer unit.
• Control Devices - can be electric or hydraulic.
• Electric Control Devices - make use of switches to move the crossheads and switch on/off the unit.
• Hydraulic Control Devices - consists of two valves, right control valve and left control valve.
• Control Unit consists of the following components: hydraulic power unit, load measuring unit, control devices
• Loading Unit consists of the following components: Load frame Upper and lower crosshead elongation scale
• Tensile test - determine the force needed to pull the specimen apart along with how much the material stretches before it breaks.
• Compression Test - opposite of tensile test where you compress an object between two level plates until a certain load or distance has been reached or the product breaks.
• Bending Stress - This is where you support a length of material by spanning it across two support on each end.
• Peel Test - this test pulls apart two materials that have been bonded together.
• Puncture Stress - you secure a circular section of material around its perimeter.
• Puncture Probe - use in puncture stress.
• Forest Service of the Department of Agriculture - has a broad management responsibility for the harvesting of wood.
• Forest Service of the Department of Agriculture produced Wood Handbook, which is an excellent document describing the characteristics and properties of wood.
• Wood is a natural, renewable product from trees
• A Tree is a woody plant that attains a height of at least 6m, normally has a single self-supporting trunk with no branches for about 1.5m above the ground and has a definite crown.
• There are over 600 species of trees in the United States.
• Endogenous Trees - intertwined fiber
• Exogenous Trees - grow from the center out by adding concentric layers of wood around the central core.
• Exogenous Trees are broadly classified as deciduous and conifers.
• Deciduous - hardwood
• conifers - softwood
• balsa - a very soft and lightweight wood that is botanically a hardwood
• conifers is also known as evergreens.
• Seasoning is the process of reducing the moisture content of timber in order to prevent the timber from possible fermentation and making it suitable for use.
• Natural or Air Seasoning - sawn into planks
• Air seasoning reduces the moisture content of the wood to 12-15 percent.
• Water seasoning - immersed in running streams of water
• Boiling in water or exposing the wood to the action of steam spray is a very quick but expensive process of seasing,
• Kiln Seasoning - is adopted for rapid seasoning of timber on large scale to any moisture content.
• Two types of kilns: progressive and compartment.
• With the kiln drying there is a little loss in strength of timber, usually less than 10 percent.
• Chemical or Salt Seasoning - common salt or urea are generally used; the latter is preferred as the corrosive action of common salt is a drawback.