The influence of semi-rigid connections on the behaviour of slender structures

In the classical analysis and design of slender frame structures, it is normally assumed that the connections of the structures are either rigidly fixed or perfectly pinned. However, the real situation is that most connections often exhibit semi-rigid characteristics. This no doubt has a significant influence on the overall behaviour of the structures such as buckling capacity and deformation. With the aim of evaluating the influence of semi-rigid connections and baseplates on the overall behaviour of slender structures, this thesis is devoted to investigating the properties of semi-rigid connections, particularly the semi-rigid baseplates in pallet racks which are usually used in the storage and materials handling industry, and then evaluating their effects on the buckling and deformation response of the structures. The investigations are carried out with the combination of theory and experiment,a nd with the utilization of a computer approacha nd engineering simplification. The rotational stiffness of baseplatesi s investigatedt heoretically and experimentally aiming at estimating the principal factors that influence the behaviour of baseplates. A beam-compressions pring model is proposedt o calculate the rotational stiffness of baseplates. The compressions pringsa re characterised by the equivalent modulus of subgrade reaction and are used to model the combined action of concrete floor and soil foundation. The initial rotational stiffness of baseplates is determined analytically and the subsequent onlinear rotational stiffness is determinedn umerically using an associatedc omputer program. The investigation showed that the rotational stiffness of baseplatesi s not only dependento n the applied axial loads but also on the subgradew hich supportst he baseplate. The experiments,w hich were conducted in the present work using concrete and timber as subgrade materials to model the effects of different subgrades, support this conclusion. A structural model for buckling analysis is presentedw hich considers the beam-column and column-baseplate semi-rigid connections. The governing equations are derived by the exact analysis of column elements They can be reduced to a transcendental function in terms of buckling load factor. The fundamental critical load of the structure is found from an engineering point of view rather than a purely mathematical point. The domain of the critical load is determined firstly and then a computer iterative approach is developed. The investigation showed that the dependence of buckling loads on the rotational stiffness of semi-rigid connections is significant. A comparison between the predicted results and those of other methods is made. Also proposed is a simplified model for deformation analysis when the structure is subjected to both axial and lateral loads. The second-order analysis is carried out where the P-b effect is considered. The initial imperfection of the structure is taken into account. The Gauss elimination procedure is used to find deformation and ultimate load. The calculated results are compared with those obtained from a finite element analysis computer program LUSAS. As one aspect of the investigation, adjustable telescopic steel props with semi-rigid baseplates are analyzed. The analysis is formulated and programmed in accordance with the new Euro-Norm and the German Standards. The computed results were compared with those of LUSAS and good agreement was achieved. Based on the results obtained, discussion is made on the design of slender frame structuresw ith semi-rigid connections. Also discussed is the procedure for the load capacity check of a slender structure with a given configuration. In addition to the results obtained in the present research about the rotational stiffness of baseplates and about its influence on structural behaviour, the investigation also demonstrated how to evaluate the rotational properties of connections and their effects on buckling and deformation of structures

A Study of the Development and Promotion of Chinese Opera Movie in Rural Areas: An Investigation and Reflection on Hunan Rural Movie of Local Opera Project in China

Chinese opera movie is a special form of art developed from the combination of traditional Chinese opera and cinematographic art. In the inheritance and development model represented by “Hunan Rural Movie of Local Opera Project”（also called “Hunan Local Opera Movie Project”）, Chinese public administrators, traditional opera artists and opera movie makers target rural areas, adhere to traditional opera culture, and explore new ways to develop and promote opera movie. They put effort into upholding orthodox opera and innovating for audience, conducting a beneficial practice of making traditional culture resonate by current rural audience again in way of producing and disseminating opera movies. Their practice has contributed to the creative development of opera movie in rural areas

A novel approach to modelling and simulating the contact behaviour between a human hand model and a deformable object

A deeper understanding of biomechanical behaviour of human hands becomes fundamental for any human hand-operated Q2 activities. The integration of biomechanical knowledge of human hands into product design process starts to play an increasingly important role in developing an ergonomic product-to-user interface for products and systems requiring high level of comfortable and responsive interactions. Generation of such precise and dynamic models can provide scientific evaluation tools to support product and system development through simulation. This type of support is urgently required in many applications such as hand skill training for surgical operations, ergonomic study of a product or system developed and so forth. The aim of this work is to study the contact behaviour between the operators’ hand and a hand-held tool or other similar contacts, by developing a novel and precise nonlinear 3D finite element model of the hand and by investigating the contact behaviour through simulation. The contact behaviour is externalised by solving the problem using the bi-potential method. The human body’s biomechanical characteristics, such as hand deformity and structural behaviour, have been fully modelled by implementing anisotropic hyperelastic laws. A case study is given to illustrate the effectiveness of the approac