Creep test results of glulam members under compression and bending were studied in this paper.The creep tests were conducted to investigate the influence of the stress level and relative eccentricity on the creep defo...Creep test results of glulam members under compression and bending were studied in this paper.The creep tests were conducted to investigate the influence of the stress level and relative eccentricity on the creep deformation of glulam members.The test results showed that the creep deformation trends of glulam members under long-term compression and bending loading were similar;the creep deformation increased with increases in both the stress level and relative eccentricity.However,the relative creep deformation decreased with the increase in both the stress level and relative eccentricity under long-term loading,and a five-parameter creep model was proposed to analyse the creep mechanism of glulam members under compression and bending.The good fitness of the test results indicated that the five-parameter model was able to accurately simulate the creep deformation of glulam compression-bending members.Moreover,a numerical model was developed using the creep equation,which was related to the parameter a and b.The simulation results were in good agreement with the test results,and the parameters a and b were correlated to the relative eccentricity and stress level,respectively.Based on the corrected parameters a and b,the relative creep deformation of glulam compression-bending members was predicted over 50 years.展开更多
In this article,the effect of the bearing elastic deformation on the performance characteristics of a cylindrical journal bearing is analyzed.The variety of simulation models covers hydrodynamic（HD） and elastohydrod...In this article,the effect of the bearing elastic deformation on the performance characteristics of a cylindrical journal bearing is analyzed.The variety of simulation models covers hydrodynamic（HD） and elastohydrodynamic（EHD） lubrication theories.The Reynolds equations governing the flow in the clearance space of the journal bearing are obtained by considering the effect of mass transfer across the fluid film.The finite element method with an iteration scheme was employed to solve both the Reynolds equation and the three-dimensional elasticity equation representing the displacement field in the bearing shell.The converged solutions for the lubricant flow and elastic deformation vector are obtained.Dynamic characteristics of the journal bearing are computed for HD and EHD theories.Numerical simulation results show that the flexibility of bearing liner has a significant influence on the performance of a cylindrical journal bearing.Indeed,the elastic deformations of the bearing liner extend the pressure area in the bearing and increase the minimum film thickness.Although,dynamic coefficient,load capacity and attitude angle decrease.展开更多
基金The research described here was supported by the National Key Research and Development Program of China(Grant No.2017YFC0703506).
文摘Creep test results of glulam members under compression and bending were studied in this paper.The creep tests were conducted to investigate the influence of the stress level and relative eccentricity on the creep deformation of glulam members.The test results showed that the creep deformation trends of glulam members under long-term compression and bending loading were similar;the creep deformation increased with increases in both the stress level and relative eccentricity.However,the relative creep deformation decreased with the increase in both the stress level and relative eccentricity under long-term loading,and a five-parameter creep model was proposed to analyse the creep mechanism of glulam members under compression and bending.The good fitness of the test results indicated that the five-parameter model was able to accurately simulate the creep deformation of glulam compression-bending members.Moreover,a numerical model was developed using the creep equation,which was related to the parameter a and b.The simulation results were in good agreement with the test results,and the parameters a and b were correlated to the relative eccentricity and stress level,respectively.Based on the corrected parameters a and b,the relative creep deformation of glulam compression-bending members was predicted over 50 years.
文摘In this article,the effect of the bearing elastic deformation on the performance characteristics of a cylindrical journal bearing is analyzed.The variety of simulation models covers hydrodynamic（HD） and elastohydrodynamic（EHD） lubrication theories.The Reynolds equations governing the flow in the clearance space of the journal bearing are obtained by considering the effect of mass transfer across the fluid film.The finite element method with an iteration scheme was employed to solve both the Reynolds equation and the three-dimensional elasticity equation representing the displacement field in the bearing shell.The converged solutions for the lubricant flow and elastic deformation vector are obtained.Dynamic characteristics of the journal bearing are computed for HD and EHD theories.Numerical simulation results show that the flexibility of bearing liner has a significant influence on the performance of a cylindrical journal bearing.Indeed,the elastic deformations of the bearing liner extend the pressure area in the bearing and increase the minimum film thickness.Although,dynamic coefficient,load capacity and attitude angle decrease.
