弹性壳结构静力与动力分析的光滑粒子法

本文通过采用移动最小二乘函数作为近似函数和完全拉格朗日方程作为近似方程来改善光滑粒子法的稳定性和数值精度;在此基础上,提出了壳结构静力分析的光滑粒子法,并完善了壳结构动力分析方法;最后,采用国际公认的壳结构的标准测试模型对静力和动力问题分别进行了验证,所得结果与已有数据吻合良好,证明了本文数值模型的有效性和可靠性,为光滑粒子法进一步在裂纹、破碎等非线性壳结构中的应用提供参考.

脚手断绳保险冲击应力计算

在我国的相应规范中明确规定吊篮脚手的配重力矩与前倾力矩的比值不得小于2,对此通过动力计算做出理论的探讨和力求解决降低冲击系数寻求可行的方法。

拉索人行桥结构的分析

拉索人行桥是一种新型结构,具有精巧的造型和显著的经济性。由于需要考虑预应力和几何非线性的影响,从而给这种结构的分析增加了难度。对拉索人行桥结构的静力与动力特性分析进行了研究,并采用能量变分原理进行了求解。通过一个算例说明了其应用。

交锁髓内钉的临床应用体会

作者报道１０２例（１０５侧）交锁髓内钉的应用体会。男８２例，女２０例，年龄１７～７５岁。股骨４５例（４６侧），包括髁上骨折４例，股骨干加粗隆部骨折４例。胫骨５２例（５４侧）。肱骨５例。手术采用不扩髓３１例（肱２，胫２２，股７），扩髓７１例（肱３，胫３０，股３８）。采用静力交锁为主，静力交锁改动力交锁６例。病理性骨折２例，其中肱骨和股骨各１例。人工股骨头置换术后骨折１例。出现髓内钉偏长１例，偏短３例。对侧皮质断裂３例。螺钉不在交锁孔内３例。感染１例。本文讨论了适应证、手术注意点和并发症的预防。并讨论了扩髓与不扩髓，静力与动力交锁问题。作者认为长骨骨折应用交锁髓内钉是极好的指征，且其范围越来越扩大。

DYNAMIC ANALYSIS OF PIPELINES LAID THROUGH ALLUVIAL VALLEY

This paper describes the dynamic characteristics of pipelines laid through alluvial valleys. We assume that the alluvial valley has a semi-cylindrical cross-section. The ground motion of alluvial valley under harmonic seismic SH waves is carried out, and the pipeline-soil dynamic interaction is taken into account. Though simple, the model may qualitatively explain the earthquake damages of pipelines laid through an alluvial river valley.

DYNAMIC FINITE LAYER-ELEMENT ANALYSIS OF SOIL-STRUOTURE INTERACTION FOR NEW-TYPE OFFSHORE PLATFORM

In this paper, a new method called dynamic finite layer--element method (DFLEM) is used to analyse the soil--structure interaction of new type offshore platforms. Some valuable results have been obtained. The results show that the DFLEM is a new effective method to analyse dynamic soil--structure interaction and can be applied widely in practice.

Matching between mechanics and thermodynamics among 4 individual strokes in a 4-stroke engine by non-circular gear mechanism

The relationship between engine mechanics and thermo-dynamics has been investigated by means of numerical simulation.The inherent mismatching between the mechanical behaviors and the thermodynamic process in internal combustion engine is identified,which is believed to be one of the important limiting factors of energy efficiency for conventional engines available in the current market.An approach for engine efficiency improvement through optimal matching between mechanics and thermodynamics(OMBMT)is proposed.An ideal matching model is defined and the conflicts due to the constraints among the mapping strokes in a 4-stroke engine are analyzed.A novel mechanical model is built for approaching optimal matching among all 4 individual strokes in a 4-stroke spark-ignition engine,which is composed of non-circular gears(NCG)and integrated with conventional slider crank engine mechanism.By means of digital mechanical model and numerical simulation,the matching gains among all 4 strokes are defined and calculated for quantifying the NCG engine efficiency improvement by comparing with a baseline engine.The potentials with the OMBMT implemented and the enhancements made by NCG mechanism for engines in terms of overall engine efficiency are reported.Based on the results achieved,it is recommended that the feasibility studies and the experimental validations should be conducted to verify the engine matching concept and effectiveness of the NCG mechanism engine model proposed,and the engine performance and NCG design parameters should be further optimized.

单层折面空间网格结构性能研究及设计

结合深圳世界大学生运动会体育中心主体育场结构设计的关键问题,剖析单层折面空间网格结构的受力机理,对其刚度与变形控制、动力特性设计、极限状态下受力破坏机理、稳定承载力及强度设计等问题进行了探讨与研究。研究表明:提高径向拟桁架体系的抗弯刚度,如增大立面拟桁架柱中构件的截面积,以及增大屋面折面或立面折面的高跨比是提高结构整体刚度的有效方式;设置肩谷环向构件能够显著减小结构的自振周期,从而减弱风振效应;应重视受力较大的拉弯主构件设计,其与节点的连接部位在施工时应重点控制焊接质量。合理设计下,单层空间折面网格结构具有良好的刚度、稳定承载力性能及变形能力,同时具有足够的安全储备,在关键部件失效的情况下不会发生连续倒塌。