Tham khảo tài liệu 'tribology lubricants and lubrication 2012 part 8', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Three-Dimensional Stress-Strain State of a Pipe with Corrosion Damage Under Complex Loading 167 characteristic distribution types of the stresses ơịp a T aif T such that according to 10 if if if P T _ . p T ơij ơiị ơiị Fig. 35. Distribution of the stress Ơ1 ơí in the absence of the outer surface fixing for ơí ri p Fig. 36. Distribution of the stress Ơ1 ơí in the absence of the outer surface fixing for T - t at 168 Tribology - Lubricants and Lubrication 0 and along the z axis at the right end uz 0 lr r2 z L A comparative analysis of the stress distributions along the assigned paths shows that at the corrosion damage center path 2 there is an almost two-fold increase of the stresses ơí as compared to the surface of the pipe without damage path 1 . The disturbing effect of corrosion damage path 6 on the stress state is clearly seen. Figures 37-39 plot the distributions of the principal stresses corresponding to the stresses ơt for different loading types when displacements are absent along the x and y axes of the outer surface of the pipe ux u r r2 J when friction is present at the inner surface Trz r r 0. From the comparison of these figures it is possible to single out several characteristic distribution types of the stresses CT P ờ CT T ơ ĩ T Ơ ĩ T T related bv 10 . uij uij uij uij uij uij Ae ae y . Figures illustrate a noticeable influence of the viscous fluid oil pipe wall friction T t nn flip ốT .p t fnrmAfinn Pmm Pĩơnrp 3Q if i s QPPD fltAf fpmptirAfnrp Qfrp s sP s Arp ct ij Ax a L x Lx ij Lx A 11 ta Ax a L. A Lx a A a g LA A x s uL L AI A LLl A a LA A x s A L s sL s a A L dominant exceeding by no less than 2-3 times the stresses developed by the action of ơr r r p 4 MPa Trz r r T0 260 Pa. In view of the fact that the temperature difference Tri - Tr21 AT 20 C exerts a dramatic influence on the formation of the stress state of the pipe the distributions of aip T and CT p T T are qualitatively similar to the CTip T T ij ij ij distribution .
