Seismic response prediction of base-isolated structures with high damping rubber bearings

To characterize the highly nonlinear hysteretic behavior of high damping rubber (HDR) bearings, a previously developed mathematical hysteresis model, rather than a simplified bilinear hysteresis model, is adopted in this study. Unilateral and bilateral seismic simulation tests of a scaled-down multistory structure isolated with HDR bearings subjected to three recorded earthquakes were conducted. Based on the unilateral test results, different sets of model parameters can be identified. The fidelity of the adopted hysteresis model is investigated by comparing the analytical predictions using all sets of identified parameters with results measured from the tests. The significant influence ascribed to different ground motion characteristics such as the effects of near-field and far-field earthquakes on modeling the hysteretic behavior of HDR bearings is observed. Besides, a feasibility study on applying the identified parameters of the adopted hysteresis model to predict the bilateral seismic responses is performed. Even though the prediction accuracy of the seismic responses is satisfactory in two orthogonally horizontal directions, the bilateral hysteretic modeling of HDR bearings requires further intensive studies considering the coupling effect under bilateral excitations.     

特种橡胶助剂——烯丙基三乙氧基硅烷制备工艺的研究

采用格氏反应一步法制备烯丙基三乙氧基硅烷,介绍了反应机理、合成工艺及诸因素对反应的影响。     

Macrotexture influence on vibrational mechanisms of the tyre–road noise of an asphalt rubber pavement

The road surface is one of the most important factors that have influence on the current traffic noise. Usually, for dense surfaces, impacts of the tyre on the pavement generate vibrations which are the dominant mechanisms in the tyre–road noise. In this study, the effect of muffling these vibrations, by the incorporation of crumb rubber (CR) from wasted tyres into asphalt pavements, has been evaluated acoustically. Close proximity measurements have been carried out to register the sound emission generated in the contact zone between a reference tyre and an experimental asphalt pavement with CR. The analysis of the measurements indicates that the incorporation of CR as well as the air voids content has less influence than the macrotexture of the road surface on the acoustical behaviour of this experimental asphalt pavement.     

加成型有机硅反应过程的实时监测

用实时傅里叶变换红外光谱仪（FTIR）对乙烯基硅橡胶和含氢硅油的加成聚合过程进行了表征，得到了基团浓度消耗比反应时间变化的曲线，结果表明，在反应过程中，硅氢基与乙烯基的浓度减少呈非线性关系，这可能是硅氢基在反应过程中与空气中的物质进行了反应，从而在消耗量上较乙烯基多的缘故。     

FZJ—1G型螺杆分装机盖胶塞机构的技术改造

为提高FJZ－1G型螺杆分装机盖塞机构的自动盖塞合格率，对该机构进行了技术改造，改造后，故障率几乎为零，盖塞合格率接近100％。     

硫化胶粉／PP共混材料的研究

研究了硫化胶粉／PP共混体系的力学性能，流动性能和热变形温度等。结果表明，利用硫化胶粉可以明显改善PP的冲击性能，而且胶粉粒径越小，改善的效果越显著，但共混体系的拉伸强度有所下降。胶粉含量在5％－15％时，共混体系的综合性能较好。     

橡胶注射模具制品缺陷及其解决措施

总结了橡胶注射模具产生的制品缺陷，并提出了相应的解决措施。     

NMMO工艺三元绿色复合薄膜的制备和表征

以纤维素、木质素和淀粉为原料,以N-甲基吗啉-N-氧化物(NMMO)为溶剂,制备三元天然高分子绿色复合膜。利用傅立叶红外光谱(FT-IR)和X射线衍射(XRD)测试了三元复合薄膜的结构,采用电子显微镜(SEM)和轻敲模式原子力显微镜(AFM)观察了该模型薄膜的表面形貌,并测定了薄膜力学性能。实验结果表明,三种天然高分子形成了均相的复合薄膜结构,表现出较好的力学性能和耐水性能。     

Relationship between normal load and dynamic co-efficient of friction on rock-rubber wear mechanism

In this study, rubber compounds were produced in varying proportions of carboxylated acrylonitrile butadiene rubber (XNBR) and natural rubber (NR) and the parameters such as cure characteristics, wear behavior against various surfaces at different normal loads, and frictional works were tested. The tensile strength and dynamic co-efficient of friction of sample containing 80 wt.% of XNBR was high compared to other samples by 2% and 10% respectively. The results of XNBR and NR vulcanizates under normal pressure ranging from 43 to 118 kPa were reported. Based on these results the relationship between normal load and dynamic co-efficient of friction has been proposed. It was also observed that sample containing 80 wt.% of XNBR exhibits lesser volume loss than compared to other samples.     

Rubber‐toughened polyamide‐6 with a low thermal expansion coefficient: effect of preferential distribution of rubber and inorganic filler

The effects of morphological changes on the thermal expansion, toughness and heat resistance of polyamide‐6 (PA)/styrene–ethylene–butylene–styrene (SEBS)/polyphenylene ether (PPE) blends were investigated. Compared with the typical ‘sea (PA matrix)–island (PPE domain)–lake (SEBS in PPE domain)’ morphology, an injection‐molded ternary blend with a preferential distribution of SEBS component at the interface between PA and PPE exhibited a low coefficient of linear thermal expansion (CLTE) in the flow direction. This low CLTE was ascribed to the deformation of SEBS and PA into a co‐continuous microlayer network structure during injection molding. Consequently, the expansion preferentially occurred towards the thickness direction. Further CLTE reduction either by a change in PA viscosity or by the selective location of an inorganic filler was examined, and its influences on impact strength and heat resistance are discussed based on transmission electron microscopy observations. © 2015 Society of Chemical Industry