tailieunhanh - Mechanical properties of solid polymer

Document "Mechanical properties of solid polymer" presentation of content: Ideal Solids, tensile properties, shear properties, compressive properties, hardness, impact strength, coefficient of friction. | 1 Mechanical Properties of Solid Polymers The properties of polymers are required firstly to select a material which enables desired performance of the plastics component under conditions of its application. Furthermore they are also essential in design work to dimension a part from a stress analysis or to predict the performance of a part under different stress situations involved. Knowledge of polymer properties is as already mentioned in the preface a prerequisite for designing and optimizing polymer processing machinery. In addition to the physical properties there are certain properties known as performance or engineering properties which correlate with the performance of the polymer under varied type of loading and environmental influences such as impact fatigue high and low temperature behavior and chemical resistance. The following sections deal with the physical as well as important performance properties of polymers. Ideal Solids Ideal elastic solids deform according to Hookean law which states that the stress is directly proportional to strain. The behavior of a polymer subjected to shear or tension can be described by comparing its reaction to an external force with that of an elastic solid under load. To characterize ideal solids it is necessary to define certain quantities as follows 3 Tensile Properties The axial force F in Fig. causes an elongation A of the sample of diameter d0 and length l0 fixed at one end. Following equations apply for this case Engineering strain 0 2 1. Mechanical Properties of Solid Polymers Hencky strain Tensile stress ơz -z Ắ Reference area A - 4 Poisson s ratio Ad dn u . A o Fig. Deformation of a Hookean solid by a tensile stress 10 Stress-Strain Behavior As shown in Fig. most metals exhibit a linear stress-strain relationship curve 1 where as polymers being viscoelastic show a non-linear behavior curve 2 . When the stress is directly proportional to strain the .

• Vật lý
• Mechanical properties of solid polymer
• Ideal Solids
• Tensile properties
• Shear properties
• Compressive properties
• Impact strength
• Environmental advances
• Husk ash incorporated high
• Strength self compacting concrete
• Environmental impact assessments
• High strength concrete
• Compressive strength
• Effect of the high temperatures
• High temperatures on the microstructure
• High strength fibre concretes
• Impact of the high temperatures
• Eastern beech Fagus orientalis Lipsky
• Compression strength
• Static bending strength
• Impact bending strength
• Shear strength
• Friction stir welding AA6061 T6
• Tensile strength
• Bending strength
• Impact energy
• Mechanical properties
• BMC Pulmonary medicine
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• Chronic obstructive pulmonary disease
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• Including cardiovascular diseases
• Waterborne epoxy
• Volume resistivity
• Abrasion resistance
• Waterborne epoxy coatings
• Polypyrrole on the electrical
• BMC Cancer
• Non–small cell lung cancer
• Incremental shuttle walking distance
• Hand grip strength
• Skeletal muscle mass
• Cancer cachexia
• BMC Geriatrics
• Older adults
• Grip stability control
• Forward reach
• Hand strength
• Dual task
• Physical health
• Wheelchair user
• Nursing homes
• Significantly improved
• Overall functional performance
• Carbohydrate polymers
• Cellulose nanofibrils
• Cellulosic fines
• X ray microtomography
• Confocal laser scanning microscopy
• Strength training
• Prostate cancer
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• Muscle mass
• Water–ethanol mixture
• Small angle X ray scattering
• Intrinsic viscosity
• Hydrodynamic volume
• BMC Musculoskeletal Disorders
• Musculoskeletal physiological processes
• Rheumatoid arthritis
• Disease activity
• Palmar pinch strength