| Bamboo has a short growth cycle and is born with good toughness and high strengthto-weight ratio.Since ancient times,raw bamboo has been an important material for structural construction.Processing bamboo into bamboo scrimber can greatly increase the weather resistance,strength and durability of bamboo,so bamboo scrimber has the reputation of ‘bamboo steel’.At present,bamboo scrimber is mainly made of panels,and the main use scenes are indoor and outdoor floors.If bamboo scrimber panels are connected in a certain way to form thin-walled components such as box-shaped and Ishaped cross-sections,and applied to the field of building structures,the advantages of bamboo scrimber can be fully utilized and good economic and social benefits can be obtained.Currently,domestic research on the component level of bamboo scrimber is lacked,and the calculation methods of related components have not been established,which limits the application of bamboo scrimber in the field of building structures to a large extent.This paper is originated from the National 13 th Five-Year Key R&D Project "Research and Engineering Demonstration of Low-rise Wood and Bamboo Structure System".Based on the great mechanical properties of bamboo scrimber,it breaks through the design ideas of solid components in traditional wood structure systems.Through theoretical derivation,experimental research,numerical simulation and comparative analysis,an exploratory study on the working performance of the axial compression rod of bamboo scrimber box column is carried out,and calculation methods are proposed.The main research work of this paper is as follows:(1)Based on the theory of thin plate buckling,using the orthotropic plate model,the calculation formula for the critical buckling stress of bamboo scrimber plate under the condition of simply supported on four sides and unidirectional uniform compression is deduced,and the finite element calculation results are used to verify it.(2)The material property experiment is carried out on 10 small specimens along the grain and 10 small specimens perpendicular to the grain;the local buckling experiment of a total of 35 axial compression members with 6 width-thickness ratios and two connection modes is carried out.the failure modes of the components under the two connection methods were analyzed,and the connection method of bamboo scrimber box column was evaluated.According to the Analysis of the experiment results and the calculation results of theoretical formulas,put forward suggestions on the limit of the width-thickness ratio of the axially compressed members of bamboo scrimber box column.(3)A total of 35 axial compression members with 7 kinds of slenderness ratios are experimented on the overall stability performance.The failure modes and ultimate bearing capacity of the component are obtained;all initial defects are equivalent to the initial eccentricity,and the initial eccentricity value of each component is deduced.(4)Considering the initial geometric imperfections,a numerical simulation research was carried out on 35 components of the overall stability performance experiment.According to the material data of the full-scale experiment results,the simulation results of different methods are compared,and the constitutive model of the bamboo scrimber material is proposed.Based on the comparison of the finite element results and the experiment results,the finite element method is evaluated.(5)Results of the overall stability experiment are compared with the results of the calculation methods for the overall stability of axial compression members in the main domestic and foreign wood structure design codes.The applicability of applying these methods to the calculation of the overall stability bearing capacity of the reorganized bamboo box section axially compressed members is evaluated. |
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