应力吸收层原材料选择标准的探讨

应力吸收层是一种新型的延缓和防止反射裂缝的结构材料,在原材料的要求方面有很多特点,我们结合室内试验对应力吸收层原材料选择标准进行了较深入的研究,并取得了一定的成果。     

涵洞整体式基础分析与设计

主要介绍涵洞整体式基础选择及设计要点,重点分析整体式基础地基承载力的深度修正,并通过计算,对整体式基础的材料选用进行了比较说明。     

橡胶改性沥青加铺应力吸收层技术研究

半刚性材料的反射裂缝问题是不可避免的。采用橡胶粉改性沥青应力吸收层技术,能够很好地解决半刚性基层裂缝反射和雨水下渗的问题。从材料、施工和检测等方面对橡胶粉改性沥青应力吸收层技术进行了研究。     

非硫酸盐高浓度有机废水酸化的可生化性指标

利用表观B/C指标和理论B/C指标评价了厌氧酸化过程对蔗糖-蛋白胨人工废水可生化性的影响.结果显示对于COD为1 064～63 900 mg/L的废水,采用表观B/C评价指标,废水的可生化性降低了0%～96%;采用理论B/C指标,可生化性提高幅度为2%～21.6%.实验结果表明用理论B/C指标评价厌氧酸化过程对蔗糖-蛋白胨人工废水可生化性的影响较之表观B/C更为科学合理;同时说明对于非硫酸盐废水类型,理论B/C作为评价其酸化过程改变废水可生化性的指标同样适用;酸化出水的理论B/C随废水COD增加呈现下降的趋势,理论分析认为其与废水的酸化度(α)有关,酸化度越低,酸化出水的理论B/C越低.     

Stress Field Analysis of Carburized Specimen and Its Numerical Simulation

IntroductionCarburiZingiswidelyaPPiedheattre8boellttechnologyinindustry.Duringcarburizing,acasewithcarboncontellthigherthanthatofthecoreisformd;andaftethecarburzedmachinepwtbeingquenched,sdsehardenedlayeconsistedmainlyofmartensite,aswellasresidualstfOssfieldappearinit.Theresidua1stressfieldofcarburizedsteelanditsinfluenceonfatiguestrengthhavebeenstudiedexPerimenally["'],whilefewrePortscanbefoundaboatnumericalsimulationofresidualstressfieldincarburizedsPecmenaswellasitsinstataneousstressdist…     

Numerical Simulation on Thermal Stress of Large-scale Bearing Roller during Heating Process of Final Heat Treatment

IntroductionThetemPeratUredifferencebforeentheinsideandoutsideofthelnye-scaleforgingworkPieceislmpewhenheatedbecauseofitsbigcross-seCtion.ThelereetCmPerforedffeencewillgeneratethermalstrCss.IfthethemalstressislargeenOugh,theforsingworkPiecewil1crack.Howtodesigntheheatingtechnology,controltheheatingProcess,avoidtheoverlargethemalstresscausingcrackisanimPortatPToblemfortheheattreWntofthelarge-scalefOrgingworkPiecel'].InthispaPeqthethermalstressevolvingProcessofthe70Cr3Mobearingrollerdur…     

Dynamic anti-plane interaction between an impermeable crack and a circular cavity in an infinite piezoelectric medium

Wave propagation in an infinite elastic piezoelectric medium with a circular cavity and an impermeable crack subjected to steady-state anti-plane shearing was studied based on Green＇s function and the crack-division technique. Theoretical solutions were derived for the whole elastic displacement and electric potential field in the interaction between the circular cavity and the impermeable crack. Expressions were obtained on the dynamic stress concentration factor （DSCF） at the cavity＇s edge, the dynamic stress intensity factor （DSIF） and the dynamic electric displacement intensity factor （DEDIF） at the crack tip. Numerical solutions were performed and plotted with different incident wave numbers, parameters of piezoelectric materials and geometries of the structure. Finally, some of the calculation results were compared with the case of dynamic anti-plane interaction of a permeable crack and a circular cavity in an infinite piezoelectric medium. This paper can provide a valuable reference for the design of piezoelectric actuators and sensors widely used in marine structures.     

出海闸复合基础的力学特性研究

通过对出海闸的整体有限元数值计算(计入复合基础的底板、桩与土的共同作用),计算其结构的位移场及应力场.结论是复合基础底板与单一基础底板的内力、位移在大小、分布、控制工况及危险点上完全不同.由于桩基对底板的作用,基础底板出现应力集中为该复合基础的明显特征.     

坝陵河大桥锚碇混凝土耐久性研究

通过试验对坝陵河大桥锚碇混凝土的渗透性进行了分析。结果表明,氯离子扩散试验得到的混凝土渗透性结果与孔结构试验结果吻合较好。同时根据试验所得的渗透系数对锚碇混凝土的耐久性寿命进行了预测,并分析总结了提高混凝土耐久性的技术措施,为混凝土结构耐久性设计提供了参考。