目的 探究C276/304L异种金属爆炸焊接过程中温度变化历程与界面微观组织形成的关系.方法 利用爆炸焊接工艺获得结合良好的复合板,观察测量复合界面的微观组织和显微硬度分布.运用ANSYS/AUTODYN数值模拟对界面形成过程进行分析,探究界面温度场变化与熔化区组织形成的内在联系.结果 对比模拟结果发现,界面在复合过程中存在高应变率及严重塑性变形而经历快速升温,界面升温速率可达2.35×109℃/s,这将导致局部区域材料发生熔化和混合,并在旋转作用下形成漩涡;而后经历快速冷却过程,冷却速率可达107～109℃/s,形成独特的熔化区组织.高温高压及高塑性变形导致熔化层产生的同时,对界面附近硬度也会产生影响.结论 熔化区组织的形成与复合过程中的高升温速率及冷却速率有关,同时界面因剧烈变形产生应变硬化.

爆炸焊复合板经压力加工后,界面两侧晶粒会出现不协调的塑性变形,从而降低产品质量.以0Cr13/Q235爆炸焊复合板为研究对象,通过施加不同的轴向载荷使复合板产生12.5％、37.5％和50％的变形;通过光学显微镜和扫描电镜等分析不同变形量下界面的微观组织形貌和显微硬度变化规律.结果表明:塑性变形量增加引起结合界面厚度下降及界面附近显微硬度整体升高,界面两侧晶粒取向趋于一致,呈现出各向异性;但当变形量增加至50％时,其硬度略有下降.

高校校园中的公共设施具有承载独特校园文化气质的功能.文章认为在高校公共设施设计中,应着重体现高校历史文化、人文精神以及道德风貌,通过提炼、解构、移植、抽象等手法,提取高校校园特有的文化元素,并结合相应理论促成与之相匹配的物质载体的设计;结合环境行为学、人机工程学以及无障碍设计理论,分析研究融合校园文化的高校公共设施设计方法,并将设计理论及方法应用在合肥工业大学公共设施的设计中,形成了系统化的高校公共设施设计探索.

Based on the shear characteristics for supporting and seismic conditions of pipe piles.The full scale experiment of the shear performance was carried out on theΦ800C80PHC pipe pile and using the finite element software to simulate.The experimental results showed that:the shear bearing capacity of test pile was slightly higher than the standard value,pipe pile cracked along the longitudinal under the action of shear force.It has a large difference with the 45°inclined cracks of small diameter pipe piles in other literature.Finite element simulation calculation shows:the calculation shear was slightly lower than the test value and the crack characteristics consistent with the test results.The finite element software can be used to deeply research the factors influencing the shear properties of the pipe pile.

文章针对存在缺陷损伤的压力管道,采取碳纤维复合材料(CFRP)的加固方式,不同的CFRP纵向加固范围会影响补强的效果.采用有限法分析压力管道加固前、后的受力性能,结果表明,环向加固CFRP可有效降低缺陷处的应力,可见CFRP 加固效果明显;并与试验模拟结果进行了比较,得出有限元与试验模拟的荷载-应力曲线的形式及变化趋势基本吻合,故合理选用有限元模型可以较好的模拟试验情况.

In order to improve the low shear capacity of prestressed concrete pipe pile and make it being widely used in supports engineering of foundations,starting from the shearing capacity formula of pipe piles,this paper put forward the crack shear concept clearly and point out that in different engineering the calculation methods of ultimate shear capacity and crack shear capacity are different in essence,by analyzing and summarizing the present researching status.At the same time,it get two methods recently used about shear calculation.One of the them considers the role of stirrups,while the other does not.Also,in this paper the problems existing in the research of shear formula about pipe piles have been noted,and several directions have been given for the further study on shear properties and shear formula of pipe piles.

Shear capacity is one of main indicators of bearing capacity of pre-stressed concrete pipe piles in the earthquake and support engineering .By using the finite element method ,three groups models are established to analyze the influence of some factors like effective pre-stress ,wall thickness and shear span ratio on the cracking shear and features of pre-stressed pipe pile .The results are as fol-lows :with the increase of the effective pre-stress and wall thickness of the pipe pile ,the cracking shear improves significantly ,w hile the shear span ratio causes little effect on the cracking shear ;the principal stress tracing line of pipe pile is opposite with that of rectangular cross-section beams and cracks develop along the pile length when the shear span ratio is relatively small .