摘要：There have been a great demand for a suitable and convenient method in the field of buckling analysis of stiffened ship structures, which is essential to structural safety assessment and is significantly time-consuming. Modeling, buckling behaviors and ultimate strength prediction of stiffened panels were investigated. The modeling specification including nonlinear finite element model and imperfections generation, and post-buckling analysis procedure of stiffened plates were demonstrated. And a software tool using set-based finite element method was developed and executed in the MSC. Marc environment. Different types of stiffen panels of marine structures have been employed to investigate the buckling behavior and assess the validity in the estimation of ultimate strength. A comparison between results of the generally accepted methods, experiments and the software tool developed was demonstrated. It is shown that the software tool can predict the ultimate capacity of stiffened panels with imperfections with a good accuracy.

摘要：Experimental study was carried out on the in-plane bending behavior of glass plates without lateral supports, and the effects of the factors, such as height-to-span ratio, on the stability of glass panels were studied. Results show that the in-plane bending glass plates with both ends simply supported and their upper edge free lose overall stability under loads, which belongs to the limit-point type of instability. It is found that the buckling load increases linearly with the increase of height-to-span ratio of the glass plates. The lateral stress of in-plane bending glass plates without lateral supports increases linearly under loads; while the large-area stress increases nonlinearly and the lateral stress is not the controlling factor of instability. In finite element analysis, the first buckling mode is regarded as the initial imperfection and imposed on the model as 1/1000 of the span of the components. The numerical buckling load according to the theory of large deflection is less than the experiment result, which is more conservative and can provide some reference for design. For the design method, when the in-plane load is imposed on the glass plate, its lateral strength and the deflection should be verified. Considering the stability of the in-plane bending glass plate without reliable lateral support, buckling is another possible failure mode and calls for verification.

摘要：The vacuum plume effects experimental system （PES） is the first experimental system designed to study the effects of vacuum plume in China. The main equipment, a vacuum chamber of 5.5 m in diameter and 12.8 m in length, and structure design of hinged door are described. The finite element method （FEM） is adopted to analyze the static strength and stability of the PES vacuum chamber. It is demonstrated that the static strength and stability are qualified. For the 5.5 m diameter vacuum chamber door, three design schemes are put forward. After comparisons are made, the single-axis-double-pin hinged door is selected. The FEM is applied to checking its static strength as well as distortions. The results show that the door’s distortion and displacement change mainly due to the gravity of the door which leads to its sinking. The calculated displacement is less than 7.8 mm, while the actual measurement is 5 mm. The single-axis-double-pin hinged door mechanism completely satisfies the design requirements. This innovative structure can be introduced as a reference for the design of large-scale hinged doors.

摘要：In this paper, a method for the design optimization of elasto-plastic truss structures is proposed based on parametric variational principles （PVPs）. The optimization aims to find the minimum weight/volume solution under the constraints of allowable node displacements. The design optimization is a formulation of mathematical programming with equilibrium constraints （MPECs）. To overcome the numerical difficulties of the complementary constraints in optimization, an iteration process, comprising a quadratic programming （QP） and an updating process, is employed as the optimization method. Furthermore, the elasto-plastic buckling of truss mem- bers is considered as a constraint in design optimization. A combinational optimization strategy is proposed for the displacement constraints and the buckling constraint, which comprises the method mentioned above and an optimal criterion. Three numerical examples are presented to show the validity of the methods proposed.

摘要：This paper presents an experimental investigation of longitudinally welded aluminum alloy I-section columns subjected to pure axial *** specimens were fabricated using 6061-T6 heat-treated aluminum *** test program included 20 column tests which were separated into 2 test series of different types of welding *** test series contained 10 *** the specimens were welded using the Tungsten Inert Gas welding *** length of the specimens ranged from 442 to 2433 mm in order to obtain a column curve for each test *** observed failure mode for the column tests includes mainly flexural buckling around the minor axis and the major axis by applying support except for one column(ZP 1217-1)which buckled in the local zone and some columns which failed in the *** test strengths were compared with the design strengths predicted by the European Code and China Code for aluminum *** purpose of this paper is to present the tests results of two typically longitudinally welded I-section columns,and to check the accuracy of the design rules in the current specifications.

摘要：With the rapid rising of heat flux and reduction of heat dissipating space of microelectronic devises, flattened sintered heat pipe has become an ideal conducting element of use in the electronic cooling field. A manufacturing technology named phase change flattening process is presented to fabricate the flattened grooved-sintered wick heat pipe （GSHP for short）. Deformation geometry of flattened GSHP and the elasto-plastic deformation of flattening process are analyzed theoretically and verified by experiments. The results show that the vapor pressure inside sintered heat pipe during flattening process is determined by the saturated vapor pressure equation; the width and vapor area of flattened heat pipe change greatly as the flattening proceeds; the maximum equivalent strain distributes at the interface between wick and vapor in the fiat section; the buckling phenomenon can be well eliminated when the flattening temperature reaches 480 K; phase change flattening punch load increases with flattening temperature and displacement.

摘要：Structural analysis of steel frames is typically performed using beam elements. Since these elements are unable to explicitly capture the local buckling behavior of steel cross-sections, traditional steel design specifications use the concept of cross-section classification to determine the extent to which the strength and deformation capacity of a cross-section are affected by local buckling. The use of plastic design methods are restricted to Class 1 cross-sections, which possess sufficient rotation capacity for plastic hinges to develop and a collapse mechanism to form. Local buckling prevents the development of plastic hinges with such rotation capacity for cross-sections of higher classes and, unless computationally demanding shell elements are used, elastic analysis is required. However, this article demonstrates that local buckling can be mimicked effectively in beam elements by incorporating the continuous strength method (CSM) strain limits into the analysis. Furthermore, by performing an advanced analysis that accounts for both geometric and material nonlinearities, no additional design checks are required. The positive influence of the strain hardening observed in stocky cross-sections can also be harnessed, provided a suitably accurate stress–strain relationship is adopted;a quad-linear material model for hot-rolled steels is described for this purpose. The CSM strain limits allow cross-sections of all slenderness to be analyzed in a consistent advanced analysis framework and to benefit from the appropriate level of load redistribution. The proposed approach is applied herein to individual members, continuous beams, and frames, and is shown to bring significant benefits in terms of accuracy and consistency over current steel design specifications.

摘要：Goal based and limit state design is nowadays a well-established approach in many engineering *** construction rules started introducing such concepts since early ***,classification societies’rules do not provide hints on how to verify limit states and to determine the structural layout of submerged thin-walled stiffened cylinders,whose most prominent examples are ***,they generally offer guidance and prescriptive formulations to assess shell plating and stiffening *** marine structures are studied,designed and built up to carry payloads below the sea *** the concept-design stage,the maximum operating depth is the governing hull scantling *** dimensions are determined based on the analysis of operational *** study proposes a practical conceptdesign approach for conceptual submarine design,aimed at obtaining hull structures that maximize the payload capacity in terms of available internal volume by suitably adjusting structural layout and stiffening members’scantling,duly accounting for robustness and construction constraints as well as practical fabrication *** proposed scantling process highlights that there is no need of complex algorithms if sound engineering judgment is applied in setting down rationally the hull scantling problem.A systematic approach based on a computer-coded procedure developed on purpose was effectively implemented and satisfactorily applied in design practice.