共查询到19条相似文献，搜索用时 687 毫秒
1.
混凝土材料动力本构模型研究进展 总被引：10，自引：0，他引：10
综述了近20年来国内外混凝土材料动力本构模型的研究状况。对国内外最新的几种混凝土动力本构模型进行了述评，指出了各种模型的适用条件及其优缺点。最后，根据现有的研究成果及混凝土材料的动力试验研究结果，得出了建立混凝土动力本构模型中应考虑的主要因素。 相似文献
2.
《世界地震工程》2016,(2)
侧向约束能够提高高强混凝土抗压强度,有效改善延性,合理本构模型的表述对结构非线性分析意义显著。基于281组三轴受压约束混凝土构件试验结果,建立了峰值应力和峰值应变与侧向约束的计算模型,并与现有Attard and Setunge模型、Candappa模型和Lu and Hsu模型、Jiang and Teng模型进行对比,评估模型的准确性;进而,采用Popovice模型,建立了适用于普通和高强混凝土的本构模型。研究表明:建立峰值应力和峰值应变模型计算值与试验值较为接近,基于其建立的高强混凝土三轴受压本构模型曲线与试验曲线吻合较好,为高强混凝土三轴受压约束构件的非线性分析提供理论依据。 相似文献
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本文对郯庐断裂带大水场黄绿色粘土型断层泥进行了一系列实验研究并初步探讨了其本构特征。该本构模型能描述断层泥的弹性性态。破坏性态和帽盖性态,适应范围较广。 相似文献
4.
饱和土体动力本构模型研究进展 总被引：11，自引：0，他引：11
饱和土体的动力本构模型对于土体的动力反应计算分析和岩土工程初边值问题的求解发挥着重要的作用。本文对饱和砂土干口饱和粘土动力本构模型的研究进展情况进行了较为详细的综述，并对其未来发展的一些方向和有待进一步研究的问题作了介绍。 相似文献
5.
《地震工程与工程振动》2020,(4)
为加强中空夹层钢管混凝土的力学性能,提出了在中空夹层钢管混凝土内外钢管间焊接双向对拉拉筋的构造措施。针对带拉筋中空夹层钢管混凝土纯弯构件受力性能开展了试验研究,研究配置拉筋对试件极限弯矩、抗弯刚度和横向变形系数的影响。采用合理的混凝土三轴受力状态本构模型和钢材本构模型,应用ABAQUS有限元软件建立并验证了带拉筋中空夹层钢管混凝土纯弯构件三维实体有限元模型,试验结果与有限元计算结果吻合良好;在此基础上,分析了拉筋对内外钢管应力及核心混凝土应力的影响,研究结果表明:拉筋能有效缓解了内外钢管的局部鼓曲,提高试件的极限弯矩、抗弯刚度;拉筋加强了内外钢管对混凝土的约束作用,使得内外钢管受力更加合理。 相似文献
6.
对一个地震突变模型的讨论 总被引：4，自引：0，他引：4
本文用非线性力学方法讨论了地震过程的非稳定现象并建立了相应的突变理论模型。文章详细讨论了断层带的本构性质和突变模型中状态变量的选取对地震非稳性的影响，揭示了用突变模型研究地震现象的可行性。 相似文献
7.
为研究地震作用下损伤累积对型钢高强混凝土框架节点抗震性能的影响,基于5榀型钢高强混凝土框架节点低周反复加载试验结果,分析节点构件损伤累积过程及其对刚度和强度的影响。从材料自身损伤入手,通过引入刚度影响系数考虑循环荷载作用下混凝土的单边效应,对Faria-Oliver本构模型进行改进,进而建立适应于型钢混凝土结构的材料损伤累积本构模型。同时基于该模型采用ANSYS分析软件对地震作用下的型钢高强混凝土框架节点进行数值分析,并与试验结果进行对比分析。结果表明:采用本文建立的材料损伤累积本构模型能较好地反映地震作用下型钢高强混凝土框架节点的损伤特性。在此基础上,进一步分析构件轴压比、配箍率、配钢率等设计参数对型钢高强混凝土框架节点抗震性能的影响。研究成果可为该类结构构件的抗震设计提供理论和技术支撑。 相似文献
8.
研究了基于纤维模型的CFT框架柱滞回性能模拟的建模方法,建立了基于不同材料本构模型的CFT框架柱数值模型,并探讨了材料本构关系、纤维截面网格划分、积分点数量等因素对模拟精度的影响。以试验为依据,运用Opensees软件,通过计算结果与试验结果的对比,分析了影响滞回模型计算精度的主要因素。结果表明,受约束混凝土本构关系的下降段,钢材本构关系的强化段,是影响滞回模型准确性的主要因素,而网格划分和积分点数量的影响则主要体现在程序运行速率方面。研究将为基于纤维模型法的CFT框架柱滞回性能模拟分析提供理论依据。 相似文献
9.
根据软弱场地土上地铁车站结构大型振动台模型试验结果,以软件ABAQU S为平台,采用记忆型嵌套面黏塑性动力本构模型和动塑性损伤模型,分别模拟土体和车站结构混凝土的动力特性,建立了土-地铁车站结构非线性动力相互作用二维和三维有限元分析模型,对各种试验工况下地基土-地铁车站结构体系的地震反应进行了数值模拟,并与试验结果进行了对比。结果表明：二维、三维数值模拟与振动台模型试验结果基本一致,三维模型可更好地模拟软弱场地与地铁车站结构的动力相互作用及模型结构的动力反应。数值模拟结果和振动台试验结果可相互验证其可靠性。 相似文献
10.
高强钢绞线网-聚合物砂浆加固钢筋混凝土板的抗爆性能数值分析 总被引：1，自引：0，他引：1
为研究高强钢绞线网-聚合物砂浆加固混凝土板的抗爆能力,用混凝土HJC动力本构模型,建立了混凝土板、炸药及考虑空气介质影响的流固耦合有限元计算模型。用动力分析软件ANSYS/LS-DYNA,对在爆炸荷载作用下加固前、后混凝土板的破坏形态和抗爆性能进行了数值分析。研究结果表明：混凝土板用高强钢绞线网-聚合物砂浆加固后,抗爆炸冲击能力明显提高。当小药量爆炸时,板顶、板底同时加固的效果明显优于板底单一加固;当药量较大时,板顶、板底同时加固的效果与板底单一加固相差不大。 相似文献
11.
A new simplified modelling strategy to simulate the non‐linear behaviour of reinforced concrete shear walls under dynamic loading is presented. The equivalent reinforced concrete (ERC) model is derived from the framework method and uses lattice meshes for concrete and reinforcement bars and uniaxial constitutive laws based on continuum damage mechanics and plasticity. Results show the capacity of the model to analyse structures having different slenderness and boundary conditions. For low reinforcement ratios however, results are sensitive to the angle formed by the diagonals of the concrete lattice and the horizontal bars. The method is compared with the shear multi‐layered beam model that uses Timoshenko multi‐layered 2D beam elements and biaxial constitutive laws. Comparisons for both models with experimental results of two research programs (one organized by NUPEC and the other by COGEMA and EDF) are provided. ERC is a simplified method that intends to save computer time and allows parametrical studies. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
12.
Owing to the devastating M7.6 earthquake of 20 June 1990 that occurred in the northern province of Iran, Sefid‐rud concrete buttress dam located near the epicenter was severely shaken. The crack penetrated throughout the dam thickness near slope discontinuity, causing severe leakage, but with no general failure. In this study, nonlinear seismic response of the highest monolith with empty reservoir is investigated experimentally through model testing. A geometric‐scaled model of 1:30 was tested on a shaking table with high‐frequency capability to study dynamic cracking of the model and serve as data for nonlinear computer model calibration. Three construction joints are set up in the model to simulate effects of construction aspects. The experimental results are then compared with smeared crack and damage mechanics finite‐element simulations using nonlinear concrete constitutive models based on fracture mechanics. The crack patterns obtained from numerical models are in good agreement with those obtained from shaking table tests for the case of including construction joint effects and rigid foundation. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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The hypoplastic constitutive model is known for its numerous application to the problems of soil mechanics and also for its excessive ratcheting. The paper shows that this deficiency can be interpreted as Liapunov instability in dynamic case. This is demonstrated with a simple one-dimensional swinger. Infinitesimally small as well as finite oscillations are analytically examined and the variability of stiffness upon a single cycle is considered. Several methods to circumvent the problem of ratcheting are discussed: implementation of ‘elastic’ range by means of so-called intergranular strain, usage of overlay modelling with parallel coupling of hypoplastic materials as originally proposed by Valanis in his endochronic theory and a special coupling of hypoplastic models based on comparison of partial stiffnesses. 相似文献
15.
The purpose of this paper is to describe how the methods and concepts of continuum damage and fracture mechanics can be applied to the modelling of the hysteretic behaviour of Reinforced Concrete (RC) frame members under variable axial loads. A frame member is considered as the assemblage of an elastic beam-column and two inelastic hinges, as in conventional nonlinear analysis of RC frames. As a result of the combination of damage mechanics and standard RC theory, a simplified model of damage is proposed and implemented as a finite element (FE). This new element can be used with any non-linear commercial FE program. The numerical simulation of several experiments, for which data were available in the literature, verifies the accuracy of the model. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
16.
The constitutive theory on the viscoelastoplasticity and damage of frozen soil is based on the continuous mechanics and thermodynamics. The basic principles of the theory, dissipation potential function and damage model are presented. The constitutive theory explains the mechanical properties of frozen soils under complicated stresses, especially under high confining pressures which make frozen soil harden and soften. The agreement between the calculated results by the constitutive theory and the experimental results of triaxial creep of frozen soil is seen to be very good. 相似文献
17.
This work focuses on the modelling issues related to the adoption of the pushover analysis for the seismic assessment of existing reinforced concrete (RC) structures. To this purpose a prototype reference structure, one of the RC shear walls designed according to the multi‐fuse concept and tested on shaking table for the CAMUS project, is modelled at different levels of refinement. The meso‐scale of a stiffness‐based fibre element and the micro‐scale of the finite element (FE) method are herein adopted; in the latter separate elements are adopted for the concrete, the steel and the steel–concrete interface. This first of the two companion papers presents in detail the wall under study, illustrating the design philosophy, the geometry of the wall, the instrumentation set‐up and the test programme. The two modelling approaches are then described; the most important points in terms of element formulation and constitutive relations for materials are presented and discussed for each approach, in the light of the particular design of the wall and of its experimental behaviour. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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19.
James R. Rice 《Pure and Applied Geophysics》1983,121(3):443-475
Constitutive relations for fault slip are described and adopted as a basis for analyzing slip motion and its instability in
the form of earthquakes on crustal faults. The constitutive relations discussed include simple rate-independent slip-weakening
models, in which shear strength degrades with ongoing slip to a residual frictional strength, and also more realistic but
as yet less extensively applied slip-rate and surface-state-dependent relations. For the latter the state of the surface is
characterized by one or more variables that evolve with ongoing slip, seeking values consistent with the current slip rate.
Models of crustal faults range from simple, single-degree-of-freedom spring-slider systems to more complex continuous systems
that incorporate nonuniform slip and locked patches on faults of depth-dependent constitutive properties within elastic lithospheric
plates that may be coupled to a viscoelastic asthenosphere.
Most progress for the rate and state-dependent constitutive relations is at present limited to single-degree-of-freedom systems.
Results for stable and unstable slip with the various constitutive models are summarized. Instability conditions are compared
for spatially uniform versus nonuniform slip, including the elastic — brittle crack limit of the nonuniform mode. Inferences
of constitutive and fracture parameters are discussed, based on earthquake data for large ruptures that begin with slip at
depth, concentrating stress on locked regions within a brittle upper crust. Results of nonlinear stability theory, including
regimes of complex sustained stress and slip rate oscillations, are outlined for rate and state-dependent constitutive relations,
and the manner in which these allow phenomena like time-dependent failure, restrengthening in nearly stationary contact, and
weakening in rapidly accelerated slip, is discussed. 相似文献