建筑用金属面夹芯板力学性能研究现状

金属面夹芯板因其良好的保温、防火、隔声等性能,作为围护结构在装配式建筑工程中得到了广泛的应用,而力学性能作为其保证安全性的基本性能在应用之初就得到了广泛的研究。随着金属面夹芯板在装配式建筑中的推广,新问题及新技术的出现使得金属面夹芯板的力学性能的研究更深入广泛。本文阐述了目前建筑用金属面夹芯板结构的分类及力学特点、金属面夹芯板力学性能的研究方法,以及金属面夹芯板在抗弯承载力、抗风荷载性能和抗冲击性能方面的研究现状。由此可知,目前对金属面夹芯板力学性能的研究已较为成熟。为了使金属面夹芯板有更广泛的应用,还需对层间不完全粘结以及在火灾、低温等特殊情况下的金属面夹芯板的力学性能做进一步的研究。     

夹芯板弯曲屈曲分析的有限条-棱方法

用有限条 -棱方法对冷弯薄壁型钢压型表面泡沫夹芯板进行了弯曲屈曲分析 ,得到了夹芯板受压面层屈曲时的临界应力、屈曲荷载及屈曲半波长 ,并与试验结果进行对比 ,理论值与试验值吻合较好     

新型混合芯材复合材料夹芯板受弯性能试验研究

研制一种真空成型工艺制作的基于轻木-泡沫混合芯材的复合材料夹芯板。采用四点弯曲力学性能试验研究复合材料夹芯板的受弯破坏形态以及芯材组分对复合材料夹芯板弯曲力学性能的影响。结果表明,复合材料夹芯板的破坏模式不同于花旗木板,表现为GFRP腹板的剪切破坏。复合材料夹芯板的抗弯承载力及刚度大于花旗木板;夹芯板提高芯材和GFRP的利用效率;随着混合芯材夹芯板芯材成分比例的不同,峰值挠度基本相同,但随着花旗木芯材比例的减小,峰值承载力和抗弯刚度降低。     

碳纤维约束与箍筋约束混凝土轴压性能对比

针对箍筋约束与碳纤维约束混凝土轴心受压力学性能,基于大量的轴心受压试验数据,分析了约束混凝土轴心受压力学性能的主要影响因素,分别建立了箍筋约束与碳纤维约束混凝土轴心受压时的峰值应力、峰值应变和极限应变的计算公式;对比分析结果表明,箍筋约束混凝土优势在于低特征值段,碳纤维约束混凝土的性能在高特征值时将超过箍筋约束混凝土。     

泡桐木复合夹芯板面内轴向承载能力分析

回顾了泡桐木复合夹芯板面内轴向承载能力试验,提出了面内轴向荷载作用下泡桐木复合夹芯板承载能力参考限值;针对既有承载力计算方法的不足,运用经典夹层结构复合材料理论,讨论了夹芯板的稳定性及参数变化对其的影响,给出了面内轴向荷载作用下轻质泡桐木复合夹芯板承载能力的计算方法,阐述了泡桐木复合夹芯板的破坏机理。分析表明,取基于弯曲和剪切共同作用的弹性屈曲荷载作为泡桐木复合夹芯板轴向承载能力的限值是比较合适的;芯材拼缝的设计、施工工艺是该夹层结构发挥承载能力的关键因素;与传统的墙板或墙体比较,泡桐木复合夹芯板具有显著的质轻而承载力高的特点。     

铝制蜂窝夹芯板的强度特性

铝夹芯结构非常适合于设计飞机、高速列车和快艇等轻型交通系统。研究目的主要是明确包含铝蜂窝状内芯的铝制夹芯板在理论和试验中的强度特性。对弯曲、轴压和侧向撞击荷载作用下的铝蜂窝夹芯板构件进行了一系列强度试验。在相应荷载作用下,运用简化理论分析蜂窝夹芯板的弯曲变形、屈曲/极限强度和破坏强度。同时也讨论了结构失效模式,并给出了试验数据。     

铝制蜂窝夹芯板的强度特性

铝夹芯结构非常适合于设计飞机、高速列车和快艇等轻型交通系统。研究目的主要是明确包含铝蜂窝状内芯的铝制夹芯板在理论和试验中的强度特性。对弯曲、轴压和侧向撞击荷载作用下的铝蜂窝夹芯板构件进行了一系列强度试验。在相应荷载作用下,运用简化理论分析蜂窝夹芯板的弯曲变形、屈曲／极限强度和破坏强度。同时也讨论了结构失效模式,并给出了试验数据。     

碳纤维混凝土单轴循环受压应力应变曲线试验研究

为了研究碳纤维混凝土的力学行为,制作混凝土试块进行单轴循环受压试验,分析碳纤维不同长度和掺量等影响因素对混凝土力学性能的影响.试验表明:掺有碳纤维的混凝土试件不仅呈现出了比较明显的延性破坏特征,而且还可以使混凝土的循环受压力学行为得到显着的提高,主要表现为提高峰值应力、峰后延性和滞回耗能能力,也减小了刚度退化程度和塑性应变累积等.基于本试验得到的结果,建立了碳纤维混凝土受压应力应变曲线方程,为碳纤维混凝土结构设计和工程应用提供了帮助.     

碳纤维织物补强加固混凝土结构研究

碳纤维织物补强加固混凝土结构技术是一种新兴的科技含量较高的建筑物加固技术,得到了工木工程界及科研单位的广泛重视.论文针对国内外近几年来在碳纤维织物基本力学性能、碳纤维织物约束混凝土受压应力-应变全曲线、碳纤维织物补强加固钢筋混凝土梁正截面及斜截面承载力、碳纤堆织物补强加固钢筋混凝土柱(包括长柱和短柱)承载力和增强抗震性...     

碳纤维织物补强加固混凝土结构的系列研究

碳纤维织物补强加固混凝土结构技术是一种新兴的科技含量较高的建筑物加固技术,得到了土木工程界及科研单位的广泛重视.天津大学土木工程系作为最早对这种加固技术进行系统研究的单位之一,近几年来已先后在碳纤维织物基本力学性能、碳纤维织物约束混凝土受压应力-应变全曲线、纤维织物补强加固钢筋混凝土梁正截面及斜截面承载力、碳纤维织物补强加固钢筋混凝土柱(包括长柱和短柱)承载力和增强抗震性能等方面进行了大量的试验研究和理论分析,取得了一批有价值的研究成果,本文对这些研究成果进行了简要的介绍.     

Composite structural panels subjected to explosive loading

Details of an extensive large-scale test programme on a series of composite structural components subjected to explosive loading are presented in this paper. The test components include conventional reinforced concrete slabs, steel fibre reinforced concrete slabs, profiled steel sheeting reinforced concrete slabs, steel–air–steel sandwich panels and steel–concrete–steel sandwich panels. A total of seventy four specimens were tested using seventeen detonation phases; with charge weight ranging between 8 and 100 kg of bare high explosives and each at stand-off distance of 5 m. The main parameters observed in the tests were the generic construction form of the materials and slab thickness. Air-blast overpressure and accelerations of the specimens were captured. A modified plasticine displacement gauge was used to measure the maximum displacement. Failure modes of each type of specimens were recorded and are presented in the paper. Major conclusions relating to structural safety are summarised.     

钢筋混凝土双向密肋夹芯保温叠合板研究

钢筋混凝土双向密肋夹芯保温叠合板由预制预应力混凝土底板、保温隔热夹芯和现浇混凝土面层组成.分析了预应力混凝土底板在施工阶段和使用阶段的受力状态,提出了钢筋混凝土双向密肋夹芯保温叠合板的设计计算方法,并对其施工工艺及质量检验提出了要求.     

The strength characteristics of aluminum honeycomb sandwich panels

Aluminum sandwich construction has been recognized as a promising concept for structural design of lightweight transportation systems such as aircraft, high-speed trains and fast ships. The aim of the present study is to investigate the strength characteristics of aluminum sandwich panels with aluminum honeycomb core theoretically and experimentally. A series of strength tests are carried out on aluminum honeycomb-cored sandwich panel specimen in three point bending, axial compression and lateral crushing loads. Simplified theories are applied to analyze bending deformation, buckling/ultimate strength and crushing strength of honeycomb sandwich panels subject to the corresponding load component. The structural failure characteristics of aluminum sandwich panels are discussed. The test data developed are documented.     

Experimental assessment of the seismic performance of a prefabricated concrete structural wall system

In this study the authors investigated experimentally the behaviour of prefabricated reinforced concrete sandwich panels (RCSPs) under simulated seismic loading through a large experimental campaign. Tests were carried out on single full-scale panels with or without openings, simulating the behaviour of lateral resisting cantilever and fixed-end walls. Tests were also carried out on a 2-storey full-scale H-shaped structure constructed by individual panels which were properly joined together. The performance and failure mode of all panels tested revealed strong coupling between flexure and shear due to the squat-type geometry of the panels. However due to their well-detailed reinforcement, all panels exhibited only a relatively gradual strength and stiffness degradation and in no case did any panel suffer from sudden shear failure. The prefabricated walls of the structural system investigated herein seem to meet all the requirements of Eurocode 8 for walls to be designed as “large lightly reinforced walls”; however this assumption should be supported with further experimental and analytical studies.     

偏压作用下混凝土夹芯墙板理论研究

混凝土夹芯承重墙板其应用对我国墙体改革有着重要的意义。目前,该墙板在轴心受压情况下的力学性能已得到充分研究。但是,对于偏压作用下其力学性能的研究很少,故采用大型通用有限元分析软件ANSYS,对偏压作用下混凝土夹芯承重墙板的力学性能进行非线性分析,研究了其在竖向偏压荷载作用下的变形特性和受力性能,提出了在偏压作用下混凝土夹芯承重墙板承载力计算公式。     

Improved manufacturing method and mechanical performances of carbon fiber reinforced lattice-core sandwich cylinder

Filament winding and twice co-curing processes were applied to make advanced carbon fiber reinforced composite (CFRC) sandwich cylinder with lattice cores. Split metallic moulds were designed and adopted for easy demoulding after winding the lattice core. The cylinders were designed with a small tapering to assure tight contact between the lattice core and the inner skin. To avoid local failure at the end of the cylinder, flange structures were placed continuously from the fibers of skins and lattices. Axial compression was carried out to reveal the mechanical behaviors of the fabricated sandwich cylinder. The experiment shows that the advanced making technology shows the promise of lattice sandwich cylinder (LSC) avoiding instability, local buckling, local cracking and debonding.     

In-plane retrofitting of masonry panels with fibre reinforced composite materials

Research activities carried out during the past years concerning the use of fibre reinforced polymers (FRP) as external reinforcement of masonry walls have shown that this system considerably improves structural stability and ductility with minimum increase in the load transmitted to foundations. However, different aspects of this retrofitting system should still be analyzed.The mechanical behaviour under in-plane compression and diagonal compression of clay masonry panels reinforced or repaired with carbon fibre reinforced polymer laminates is experimentally assessed in this paper. The results show that if correct retrofitting schemes are chosen, reinforcement and repairing with fibre reinforced polymers improves masonry behaviour, increasing ductility and, in some cases, ultimate strength and even stiffness. In this way, brittle behaviour and sudden failure of unreinforced masonry can be avoided.     

Response of pre-cast reinforced composite sandwich panels to axial loading

This paper summarises the results of an experimental and numerical study of precast reinforced composite sandwich panels. Full-scale tests were carried out to determine their axial strength capacity. Load–deformation response, strains variation across the insulation layer, strains in shear connectors, crack appearance and propagation under increasing load were recorded and analysed. A brief review of previous research works undertaken on the load bearing capacity of reinforced concrete solid walls is presented. Test results and finite element analysis (FEA) results were compared with calculated values based on current ACI design practice and other available design formulations developed for solid walls to determine if these empirical formulae are also applicable for sandwich panels. A semi-empirical formula was proposed to better fit the experimental and the FEA results.     

空间格构腹板增强泡沫夹芯复合材料-试件准静态压缩吸能试验

采用聚氨酯泡沫作为填充材料,玻璃纤维增强复合材料作为面层和腹板,将双层正交格构腹板改变为双层错位格构腹板、多层错位格构腹板、六边形格构腹板和多层梯形格构腹板,制作空间格构腹板增强泡沫夹芯复合材料试件。对试件开展准静态压缩试验,记录试件的破坏过程,得到其荷载 位移曲线。分析试件产生不同破坏形式的原因,对比试件在压缩变形过程中承载力变化情况;引入能量吸收值、比吸能和平均压溃力3个指标比较试件的吸能性能。结果表明:改变竖直格构腹板的空间位置后,试件的准静态压缩破坏模式由竖直格构腹板突然屈曲失稳破坏改变为竖直格构腹板先产生倾斜再发生弯曲破坏,以及斜向格构与泡沫的剥离破坏和斜向格构与斜向格构的层间剥离破坏,有效减少了试件承载力的弹性突变,降低了试件的脆性;竖直格构腹板弯曲破坏比斜向格构的剥离破坏吸收更多能量,其能量吸收值波动幅度最大为16.6%;试件的能量吸收值随着压缩量增加呈线性增加,其耗能性能较为稳定。     

混凝土夹芯承重墙板的有限元分析

采用有限元软件ANSYS分析了3种尺寸的混凝土夹芯承重墙板的轴向受压力学性能,并与试验结果进行了对比分析,结果表明,有限元计算的构件的荷载-应变曲线和极限荷载与试验值吻合,混凝土夹芯承重墙板在轴向荷载下首先在中部开裂,然后出现受压破坏。墙板中的钢丝网延缓了裂缝的出现,调整了板中内力的分布,增强了混凝土板的承压性能。