In order to analyze the influence of flange width-thickness ratio on fire-resistant behavior of unprotected restrained steel beams in fire, finite element analysis software ANSYS is used to simulate restrained steel beams under thermal effects. After thermal-structure coupling analysis of the steel beams, results show that temperature distribution of H-section steel beam is non-uniform, and a large deflection will occur at a restrained steel beam under thermal effects. Furthermore, this paper analyzes the influence of flange width-thickness ratios on fire-resistant behavior of restrained steel beam under thermal effects by comparing factors of axial force and mid-span deflection.

The microstructure, responding degree and main properties of unsaturated polyester modified with polyurethane were studied with SEM, FT-IR, contact angle and mechanical properties testing.The study showed that with the addition of polyurethane, the toughness of unsaturated polyester was improved, the interface soaking with natural fiber was increased and the curing shrinkage rate was lowered.The impact fracture section of modified unsaturated polyester showed ductile failure.The interface soaking with natural fiber was increased when the contact angle was lowered with the increase of polyurethane content.The testing of mechanical properties showed that when the content of PU was 5%, the impact strength was increased by 80%, the decrease of flexural modulus was less than 20% and the curing shrinkage rate was less than 4%.

In this paper the surface of ramie sisal fiber was treated with A-151 and KH-550 silicane coupling agents.The mechanical performance of ramie and sisal fiber reinforced unsaturated polyester(UP) and phenolic composites before and after fiber treated were compared and analyzed.The results showed that the coupling treatment not only increased the mechanical performance obviously but also reduced the water absorption of the composites.

采用甲基丙烯酸甲酯、丙烯腈接枝,硅烷偶联剂(A-151)偶联,聚氯乙烯(PVC)包覆等方法对苎麻落麻纤维进行表面处理;测试了处理前后落麻纤维的吸水率、单丝强度及其与环氧树脂(EP)、酚醛树脂(PF)和不饱和聚酯(UP)等的接触角;观察了偶联和包覆后落麻纤维的表面状况;选取偶联和包覆后的落麻纤维制备了UP/落麻毡和PP/落麻纤维复合材料,测试了其拉伸和弯曲性能并观察了处理前后复合材料的拉伸断面形貌.结果表明,接枝、偶联和包覆不仅降低了落麻纤维的吸水速率,而且也降低了平衡吸水量;接枝对落麻纤维单丝强度影响最大,偶联次之,包覆最小;接枝、偶联和包覆均能大幅度改善落麻纤维与EP、PF和UP的浸润性;偶联和包覆后的落麻纤维表面都比处理前粗糙;偶联使UP/落麻毡复合材料的拉伸强度、拉伸弹性模量提高了21%,弯曲强度提高了34%,弯曲弹性模量提高了40%,包覆使PP/落麻纤维复合材料的拉伸、弯曲强度提高了20%左右.

本文论述了地下理设的玻璃钢管道在内压作用下,管件处产生的不平衡推力及其计算方法.为抵抗这种推力防止管件发生滑移而影响其密封性,必须对管件及其附属设备采用止推或锚固措施.为此,本文介绍了常用止推和锚固方法及其简单计算.