Computer Modeling: an Important Tool in Materials Processing

IntroductionComPlltermodelinghasenjoyedgrowingaccePtanceinindustryandacademiaasamethodofchoiceforcharaCterzingmaterialsProcessingoperationswiththedriofattainingtargotend-designsinteffosofmetricssuchasPropenies,geometw,integrityandqualityassessment.Melting,cashng,machining,joiningandheattreatmcntaresomeexamPlesofcommonmatorialsProcesses.MaterialsProcessesbytheirnaturehaveseveralinherntpthelsthatneedtobeoveromeinorderthatthedesiredProductswillmeetthetargetspecilications.SuchpitfalsrePresentb…     

甬台温高速公路瑞安段真空预压软基处理效果分析

甬台温高速公路瑞安段软基施工过程中采用真空预压处理，取得了良好的成效，工期提前，工后沉降减少，经济效益和社会效益显著。     

水泥稳定土的材料对强度的影响

水泥稳定土的强度随剂量的增加而增加,但并不是剂量越大越好.强度还与土的级配有关,改善土的级配,更能提高水泥稳定土的强度.而且改善集料的级配以减少水泥用量是减少水泥稳定土基层裂缝的重要措施之一.不同类型的水泥稳定土,要达到相同的强度,不能规定同样的剂量.     

掺粉煤灰降低水泥稳定砂砾底基层裂缝初探

从掺加粉煤灰,降低水泥用量角度着手,尽量解决水泥稳定砂砾底基层裂缝的共性问题,同时对按此方案施工易出现的问题提出解决思路。     

前轮鼓式制动器分析研究与设计计算(1)

通过对设计定型阶段复制的样件进行全性能测试、制动测试、破坏性测试、耐久性测试、相关件的强度试验和分析后证明,采用增加制动器制动力矩的技术方案,完全能达到GB 20073—2006标准中对摩托车和轻便摩托车制动性能及试验方法的要求。     

岩质边坡静动力稳定性分析

提出了有限元强度折减法在岩质边坡静动力稳定性分析中的失稳判据,结合岩质高边坡,用有限元强度折减法分析了边坡在静动力作用下的稳定性,求得安全系数与用简化B ishop法和拟静力法求得结果相差不大,证明有限元强度折减法在岩质高边坡稳定性分析中的可行性。     

谈混凝土结构质量检测

成品混凝土质量检测是工程结构安全和质量评价的重要手段,全面介绍了混凝土结构强度和损伤检测的方式和方法,为工程质量检测提供借鉴。     

关于城市桥梁大件车辆荷载的设计分析

德阳市嘉陵江公路大桥设计中,桥梁结构需要通过大件车辆荷载,该车辆荷载为QGZH490型400 t全挂车荷载,已经远远超过现行规范荷载标准。重点介绍了针对该特种车辆荷载进行的专项设计分析。     

某散货船结构强度的有限元分析

散货船由于结构问题引起安全性事故较多,为确保航行的安全性,结构强度校核是重要措施,对人命、财产安全以及环境保护具有很强的现实意义。本文以一散货船为实例船,采用有限元方法,进行强度校核,强度分析结果表明该船强度符合船级社规范要求。     

Design of offshore structures against accidental ship collisions

In this paper, we investigate the damage to offshore platforms subjected to ship collisions. The considered scenarios are bow and stern impacts against the column of a floating platform and against the jacket legs and braces. The effect of the ship–platform interaction on the distribution of damage is studied by modeling both structures using nonlinear shell finite elements. A supply vessel of 7500-ton displacement with bulbous bow is modeled. A comprehensive numerical analysis program is conducted, and the primary findings are described herein. The collision forces from the vessel are compared with the suggested force–deformation curves in the NORSOK code. For collisions with floating platforms we particularly focus on the crushing behavior and potential penetration of the bulbous bow and stern sections into the cargo tanks or void spaces of semi-submersible platforms. For fixed jacket platforms we investigate whether jacket braces can penetrate into the ship without being subjected to significant plastic bending or local denting.Adequate treatment of the relative strength between the interacting bodies is especially relevant for impacts with high levels of available kinetic energy, for which shared energy or strength design is aimed at. Simplifying one body as rigid quickly leads to overly conservative and/or costly solutions, and is in some cases non-conservative.The numerical analysis is used to develop a novel pressure–area relation for the deformation of the bulbous bow and stern corners of the supply vessel. Procedures for strength design of the stiffened panels are discussed. Refined methods and criteria are proposed for strength design of platforms, including both floating and jacket structures. The adequacy of the NORSOK design guidance for collisions against jacket legs is evaluated. The characteristic strength of a cylindrical column is used to develop a novel criterion for the resistance to local denting from stern corners and bulbous bows.