In order to decrease the deformation and stress and increase the natural frequency of the fixed table,a method of optimization driven by the sensitivity and topology analyses is proposed.The finite element model of th...In order to decrease the deformation and stress and increase the natural frequency of the fixed table,a method of optimization driven by the sensitivity and topology analyses is proposed.The finite element model of the fixed table is constructed and analyzed by using ANSYS software.Based on the results of static analysis and modal analysis,the maximum deformation,the maximum stress,and natural frequencies are obtained.Then,the sensitivity analysis and topology optimization are carried out to find out the parameters to be optimized.The fixed table is reconstructed according to optimal design scheme.In the comparison of the results between original model and the optimized one,the maximum deformation and stress are decreased by 71.73%and 60.27%respectively.At the same time,the natural frequencies from the first mode to the sixth mode are increased by 30.28%,29.57%,29.51%,31.52%,22.19%,and 21.80%,respectively.The method can provide technology guide for the design and optimization of machining structure.展开更多
This study examined the biological response of two porous calcium phosphate ceramics, hydroxyapntite ( HA ) and hydroxyapaptite/β-tricalcium phosphate ( HA/β- TCP ) scaffolds. Three different cell types , a huma...This study examined the biological response of two porous calcium phosphate ceramics, hydroxyapntite ( HA ) and hydroxyapaptite/β-tricalcium phosphate ( HA/β- TCP ) scaffolds. Three different cell types , a human osteoblastic cell line ( HOS ) , primary human osteoblasts (HOB) and human mesenehymal stem cells (MSCs), were used to examine biocompatibility and osteoinductive capacity. The experimental results showed both materials were highly biocompatible and proliferation was significantly greater on pure HA ( P 〈 0.01 ), with a peak in proliferation at day 7. Protein levels were significantly higher ( P 〈 0.05) than the control Thermanox( TMX ( tm) ) for both test materials. Osteoinduction of MSCs was observed on both test materials, with cells seeded on HA/ β-TCP showing greater alkaline phosphatase activity compared to HA alone, indicating an enhancement in osteoinductive property. Both materials show good potential for use as tissue engineered scaffolds.展开更多
基金National Major Scientific&Technological Special Program for"High-Grade CNC and Basic Manufacturing Equipment"of China(No.2012ZX04011-031)Science and Technology Programs of Sichuan Province,China(No.2010GZ0250,No.2011GZ0075)
文摘In order to decrease the deformation and stress and increase the natural frequency of the fixed table,a method of optimization driven by the sensitivity and topology analyses is proposed.The finite element model of the fixed table is constructed and analyzed by using ANSYS software.Based on the results of static analysis and modal analysis,the maximum deformation,the maximum stress,and natural frequencies are obtained.Then,the sensitivity analysis and topology optimization are carried out to find out the parameters to be optimized.The fixed table is reconstructed according to optimal design scheme.In the comparison of the results between original model and the optimized one,the maximum deformation and stress are decreased by 71.73%and 60.27%respectively.At the same time,the natural frequencies from the first mode to the sixth mode are increased by 30.28%,29.57%,29.51%,31.52%,22.19%,and 21.80%,respectively.The method can provide technology guide for the design and optimization of machining structure.
文摘This study examined the biological response of two porous calcium phosphate ceramics, hydroxyapntite ( HA ) and hydroxyapaptite/β-tricalcium phosphate ( HA/β- TCP ) scaffolds. Three different cell types , a human osteoblastic cell line ( HOS ) , primary human osteoblasts (HOB) and human mesenehymal stem cells (MSCs), were used to examine biocompatibility and osteoinductive capacity. The experimental results showed both materials were highly biocompatible and proliferation was significantly greater on pure HA ( P 〈 0.01 ), with a peak in proliferation at day 7. Protein levels were significantly higher ( P 〈 0.05) than the control Thermanox( TMX ( tm) ) for both test materials. Osteoinduction of MSCs was observed on both test materials, with cells seeded on HA/ β-TCP showing greater alkaline phosphatase activity compared to HA alone, indicating an enhancement in osteoinductive property. Both materials show good potential for use as tissue engineered scaffolds.