In order to obtain any probability of survival for crack growth life, a randomization method of deterministic equation for probability fracture mechanics is presented. According to this method, the deterministic equat...In order to obtain any probability of survival for crack growth life, a randomization method of deterministic equation for probability fracture mechanics is presented. According to this method, the deterministic equation of fracture mechanics is randomized to stochastic equation, and the parameters of the stochastic equation are estimated by means of the statistics. Three new kinds of random models to gain the p d a/ d N Δ K curve and the γ p d a/ d N Δ K curve (confidence level probability of survival fatigue crack growth rate stress intensity factor range curve) are proposed by using this randomization method. And the p d a/ d N Δ K curves and the γ p d a/ d N Δ K curves determined by these three models are discussed and compared according to the treatment result of the experimental data from CT specimens. From examples, it is found that the three deterministic fatigue crack growth rate equations determined by these models are very near and in agreement with the traditional deterministic fatigue crack growth rate equation, and these models are effectively and easily used to treat fatigue crack growth rate data.展开更多
目的探讨入院时不同程度创伤严重度评分(injury severity score,ISS)骨折患者的严重创伤者生存概率(probability of survival,PS)、全身炎症反应综合征(system ic inflam m atory response syndrom e,SIR S)发生率、平均动脉压(M AP)、...目的探讨入院时不同程度创伤严重度评分(injury severity score,ISS)骨折患者的严重创伤者生存概率(probability of survival,PS)、全身炎症反应综合征(system ic inflam m atory response syndrom e,SIR S)发生率、平均动脉压(M AP)、血红蛋白(H b)、红细胞压积(H C T)、白细胞总数(W BC)、中性粒细胞百分比(N EU T%)、血小板计数(PLT)、平均血小板分布宽度(PD W)、平均血小板体积(M PV)、大血小板比率(PLC R)、纤维蛋白原(Fbg)、总蛋白(TP)、白蛋白(ALB)、尿素氮(U R EA)、血肌酐(Scr)的变化及意义。方法回顾分析2001～2005年骨折患者226例,根据ISS分为轻度创伤组(ISS<16分)、中度创伤组(ISS16～24分)和严重创伤组(ISS≥25分)。利用TR ISS法统计每个患者的严重创伤者生存概率(PS)。对轻度创伤、中度创伤与严重创伤组间PS、SIR S发生率及入院后M AP、血常规、凝血、生化指标进行比较。结果中度创伤组M AP、H b、M PV、PLC R、Fbg、TP、ALB低于轻度创伤组,W BC、N EU T%、SIR S发生率、Scr高于轻度创伤组;严重创伤组M AP、PS、H C T、Fbg、TP、ALB低于中度创伤组,W BC、N EU T%、SIR S发生率高于中度创伤组,M AP、PS、H b、H C T、M PV、PLC R、Fbg、TP、ALB均低于轻度创伤组,W BC、N EU T%、SIR S发生率、U R EA及Scr高于轻度创伤组,差异有统计学意义。骨折患者Scr与ISS评分(r=0.273,P=0.000)、W BC(r=0.310,P=0.000)呈正相关,与PS(r=-0.202,P=0.003)、PD W(r=-0.165,P=0.018)、M PV(r=-0.193,P=0.005)、PLC R(r=-0.185,P=0.008)、Fbg(r=-0.172,P=0.017)、TP(r=-0.275,P=0.000)和ALB(r=-0.197,P=0.004)呈负相关。结论中度创伤组血压、血红蛋白、血小板体积、Fbg、血浆蛋白显著降低,W BC、N EU T%、SIR S发生率、Scr显著升高,严重创伤组除上述变化外,PS显著降低。Scr随ISS、W BC增加及PS、PD W、M PV、PLC R、Fbg、TP、ALB降低而升高,中度创伤组、严重创伤组肾功能发生改变,对骨折患者应加强肾功能检测�展开更多
文摘In order to obtain any probability of survival for crack growth life, a randomization method of deterministic equation for probability fracture mechanics is presented. According to this method, the deterministic equation of fracture mechanics is randomized to stochastic equation, and the parameters of the stochastic equation are estimated by means of the statistics. Three new kinds of random models to gain the p d a/ d N Δ K curve and the γ p d a/ d N Δ K curve (confidence level probability of survival fatigue crack growth rate stress intensity factor range curve) are proposed by using this randomization method. And the p d a/ d N Δ K curves and the γ p d a/ d N Δ K curves determined by these three models are discussed and compared according to the treatment result of the experimental data from CT specimens. From examples, it is found that the three deterministic fatigue crack growth rate equations determined by these models are very near and in agreement with the traditional deterministic fatigue crack growth rate equation, and these models are effectively and easily used to treat fatigue crack growth rate data.
