Tham khảo tài liệu 'optoelectronics materials and techniques part 13', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | An Analytical Solution for Inhomogeneous Strain Fields Within Wurtzite GaN Cylinders Under Compression Test 349 to constant strain without end friction and a 1. Fig. 4 shows the normalized axial strain zz 0 versus the normalized vertical distance z h for various values of a for r R and r R and 0 is the axial strain of the cylinder under compression without end friction and can be calculated according to 7 . shows that the axial strain is also inhomogeneous and the maximum values can be more than 40 and 30 for r R and r R respectively comparing to that without end friction. Fig. 5 shows the normalized strain h 0 versus the normalized vertical distance z h for various values of a for H 101 r R and r R and 0 is the strain of the cylinder under compression without end friction and can be calculated according to 58 . shows that the normalized strain h 0 is quite inhomogeneous and the maximum values can be 100 and 53 more than those without end friction for r R and r R respectively. Overall the inhomogeneous strain distributions are induced in the cylinder as long as friction exists between the end surface and the loading platens and the larger the friction on the end surfaces that is the smaller the value of p the more non-uniform inhomogeneous strain is induced within the cylinder. The strain distributions within cylinder for different shape of cylinder All of the numerical calculations given above are for h R . In order to investigate the shape effect on the strain distribution within cylinder under compression with end friction Figs. 6-8 plot the normalized strains rr 0 gg 0 and zz 0 versus the normalized vertical distance z h from the center of the cylinder for various values of h R for r R and p . Figs. 6-8 show that a larger deviation may be induced for shorter cylinder. For example 35 error in H 0 can be induced even at the center of the cylinder for h R . But the strain distributions for long .
