The experimental study and numerical simulation have been done aiming at the problems of dieless thin - walled tube forming under combinatory action of internal pressure and axial force and loading control stability 摘要针对内压和轴压共同作用下的薄壁管无模内高压成形及加载控制稳定性问题进行了实验及数值模拟。
According to the observed results near the fracture surfaces , the orientations of the fatigue crack initiation and propagation were investigated to study the mechanism of multiaxial fatigue crack propagation 根据薄壁管拉扭复合载试件断口附近表面观测结果，统计其裂纹扩展的位向，研究多轴疲劳裂纹萌生及扩展机理。
In this paper , thin wall tube initial yield under the pressure of hydraulic pressure , axial pressure , is discussed , the calculate formulae of initial deformation force is derived and experimental verification has been finished 摘要本文就有限长薄壁管在内压、轴力作用下初始屈服问题进行了研究，推导出了初始力计算公式，并进行了实验验证。
Abstract : a new method of machining tube parts was put forward and local upsetting tube parts can be manufactured by this method . it is important to raise mechanical strength , improve the quality and reduce production costs 文摘:提出一种新的加工薄壁管类件的方法，利用该方法可以加工局部变粗的各种形状的管类件，这对于提高工件的结构强度、材料的利用率和降低工件的重量及制造成本具有重要的意义。
In the experiment , two kinds of tubes with alternative diameters and material properties , and three kinds of flat - nosed cylindrical missiles with same length and various diameters are applied . two classes including six operating modes are designed in the experiment 在实验方面，本文采用了两种不同直径和材质的薄壁管试件以及三种长度相同，直径不同的平头弹体，设计了两大类六种工况下的实验。
The numerical control ( nc ) tube bending process used as a method of thin walled tube bending has been widely applied in fields of aeronautics and astronautics . however , the process planning based on the traditional " trial - and - error " method limits the predominance of this advanced process 数控弯管工艺在航空、航天工业的薄壁管弯曲成形中占有重要地位，但传统的基于经验和试验的工艺设计方法限制了数控弯管工艺优势的发挥。
Based on the work of former researchers , the mechanical properties of the material of the pipe pile are studied in this thesis by indoor experiment ; also the bearing mechanism is analysed combined with the famous geotechnical fem software plaxis and the influences of length of pile , diameter and the ratio of the stiffness of pile to the stiffness of soil on the bearing mechanism are discussed 本文针对现浇混凝土薄壁管桩(简称pcc桩)这种新桩型，在前人工作的基础上，通过室内试验对桩体材料的强度特性进行了研究；引入了荷兰开发的大型岩土工程有限元软件plaxis程序，对pcc单桩承载特性进行了研究，着重分析了桩长、桩径、桩土刚度比等因素对单桩承载特性的影响。
By the experiment of tension and torsion test of thin walled tube on mts , the experimental strain increment was obtained and compared with theoretical strain increment which obtained by simulation with m value 2 and the identified m value . the results of comparison validated the correctness of identified m and deformation control method using the identified m 本文在mts实验机上进行了薄壁管拉扭实验，首先进行了识别材料物性参数m值的实验，通过实验中各阶段的实际应变增量值与m值识别前后计算所得理论应变增量值的比较，验证了识别所得m值的正确性以及根据识别所得m值进行应变控制可行性。
Nowadays , the pcc pile have been widely used for soft ground improvement and application of foundation engineering . the behavior of pcc pile , that subjected to lateral load has been studied in this paper . the behavior of the pcc pile has involved moment and horizontal displacement and load of pcc pile . they are studied by in the physical model experimen , field test finite element numerical analysis , and exponential progression solution . in additional , the comparatively computal analysis are carried out among pcc pile , cast - in - situ concrete circular pile , prefabricate concrete square pile , and obtain some signification conclusion 本文主要围绕现浇混凝土薄壁管桩(以下简称pcc桩)这一新型的桩基结构型式的水平承载性状展开研究，通过室内模型试验、现场试验、有限元数值模拟分析试验及弹性幂级数解析法分析等手段，对pcc桩水平承载的桩身受力性状，桩身挠曲位移，桩身弯距分布，桩与桩周土相互作用的地基反力等几方面进行了初步的探讨和研究，最后将pcc桩与目前工程中的两种常用于承受水平荷载的桩型进行对比计算分析，得到有意义的结论。
As a new foundation improvement technology , the cast - in - situ concrete thin - wall pipe pile ( pcc pile ) is applied widely in the construction of the highway , civil architecture , haven and sea embankment etc . the pcc pile has a great prospect because it has superiority in the treatment of soils , such as construction period , cost and environment protection 现浇混凝土薄壁管桩(简称pcc桩)及其复合地基是一种全新的地基处理新技术，已应用于高速公路、民用建筑、港口、海堤等工程建设中， pcc桩在处理效果、工期、造价、环保等方面具有较大的优越性，因此在地基处理中具有广阔的应用前景。
