Crushing Behaviors of Frac tai Hexagonal Tubular Structures: Experiments and Plastic Analysis

Fractal tubular structures(FTSs)can greatly increase the anti-crushing and energy absorption capacity of the material.To reveal this mechanism,fractal hexagonal tubes(FHTs)with self-similar fractal structure were designed and prepared.Compression experiments were carried out to verify the crushing modes of structures with different scale factors.Compared with the single-cell structure,FHTs have much greater mean crushing force(MCF).According to the experiments and the numerical simulations,when the side length of the second-order hexagon is 0.3 times of the length of the first-order primary hexagon,the FTS has the greatest peak force(PF)and MCF as well as the most excellent energy-absorbing ability.Three folding styles were revealed by the experiments and the numerical simulation when changing the scale factor,including the overall folding mode,the local foaling mode and the hybrid folding mode.Theoretical plastic models were built,which consistently predicted the MCF.

Stability and reinforcement analysis of rock slope based on elasto-plastic finite element method

The rigid body limit equilibrium method(RBLEM) and finite element method(FEM) are two widely used approaches for rock slope's stability analysis currently. RBLEM introduced plethoric assumptions; while traditional FEM relied on artificial factors when determining factor of safety(FOS) and sliding surfaces. Based on the definition of structure instability that an elasto-plastic structure is not stable if it is unable to satisfy simultaneously equilibrium condition, kinematical admissibility and constitutive equations under given external loads, deformation reinforcement theory(DRT) is developed. With this theory, plastic complementary energy(PCE) can be used to evaluate the overall stability of rock slope, and the unbalanced force beyond the yield surface could be the identification of local failure. Compared with traditional slope stability analysis approaches, the PCE norm curve to strength reduced factor is introduced and the unbalanced force is applied to the determination of key sliding surfaces and required reinforcement. Typical and important issues in rock slope stability are tested in TFINE(a three-dimensional nonlinear finite element program), which is further applied to several representatives of high rock slope's stability evaluation and reinforcement engineering practice in southwest of China.

Analysis of fluoxetine-induced plasticity mechanisms as a strategy for understanding plasticity related neural disorders

Fluoxetine hydrochloride,better known for its commercial name Prozac,is one of the most widely prescribed antidepressant drugs all over the world.This drug was considered a＂breakthrough drug＂for the treatment of depression because of its very high selectivity as a serotonin reuptake inhibitor and because it presented a lower side-effectprofile than previous drugs （Wong et al., 2005）.

NONSMOOTH MODEL FOR PLASTIC LIMIT ANALYSIS AND ITS SMOOTHING ALGORITHM

By means of Lagrange duality of Hill＇s maximum plastic work principle theory of the convex program, a dual problem under Mises＇ yield condition has been derived and whereby a non-differentiable convex optimization model for the limit analysis is developed. With this model, it is not necessary to linearize the yield condition and its discrete form becomes a minimization problem of the sum of Euclidean norms subject to linear constraints. Aimed at resolving the non-differentiability of Euclidean norms, a smoothing algorithm for the limit analysis of perfect-plastic continuum media is proposed. Its efficiency is demonstrated by computing the limit load factor and the collapse state for some plane stress and plain strain problems.

PLASTIC LIMIT ANALYSIS OF INCOMPATIBLE FINITE ELEMENT METHOD

This paper describes an incompatible finite element model satisfying the consistency condition of energy to solve the numerical precision problem of finite element solution in perfectly plastic analysis. In this paper the reason and criterion of the application of the model to plastic limit analysis are discussed, and an algorithm of computing plastic limit load is given.

PLASTIC LIMIT ANALYSIS OF DISCONTINUOUS LINING UNDERGROUND PRESSURE

Discontinuous lining is a special form of support in underground excavation. Based on the method of plastic limit analysis, it is found the upper and the lower bound solution of the pressure of circular discontinuous lining and discussed support parameter of discontinuous lining and its applicable conditions , which provides theoretical basis for the design and calculation of discontinuous lining.

Elasto-plasticity and pore-pressure coupled analysis on the pullout behaviors of a plate anchor

A numerical method is proposed for the elasto-plasticity and pore-pressure coupled analysis on the pull- out behaviors of a plate anchor. The bounding-surface plasticity （BSP） model combined with Blot＇s consol- idation theory is employed to simulate the cyclic loading induced elasto-plastic deformation of the soil skeleton and the accompanying generation/dissipation of the excess pore water pressure. The suction force generated around the anchor due to the cyclic variation of the pore water pressure has much effect on the pullout capacity of the plate anchor. The calculated pullout capacity with the proposed method （i.e., the coupled analysis） gets lower than that with the conventional total stress analysis for the case of long-term sustained loading, but slightly higher for the case of short-term monotonic loading. The cyclic loading induced accumulation of pore water pressure may result in an obvious decrease of the stiffness of the soil-Plate anchor svstem.

竹纤维增强塑料埋地管道应用与理论分析

纤维增强复合材料是一种新型结构材料,具有一系列的优点。随着管道制备工艺的发展和高分子材料在管道中的应用,竹纤维增强塑料管材,作为一种新型材料,正在逐渐替代传统的管材。考虑各种影响因素,对竹纤维增强塑料管材的进行理论分析,并进行了管材的埋地试验,两者结果差异甚小,均满足工程要求。

Numerical Analyses of Bearing Capacity of Deep-Embedded Large-Diameter Cylindrical Structure on Soft Ground Against Lateral Loads

Presented in this paper is a three-dimensional plastic limit analysis method of bearing capacity of the deeply-embedded large-diameter cylindrical structure in the cross-anisotmpic soft ground. The most likely failure mechanism is assumed to be of a composite rupture surface which is composed of an individual wedge in the passive zone or two wedges in both active and passive zones near the mudline, depending on the separation or bonding state at the interface between the cylindrical structure and neighboring soils in the active wedge, and a truncated spherical slip surface at the base of the cylinder when the structure tends to overturn around a point located on the symmetry axis of the structure. The cylindrical structure and soil interaction system under consideration is also numerically analyzed by the finite element method by virtue of the general-purpose FEM software ABAQUS, in which the soil is assumed to obey tie Hill＇s criterion of yield. Both the failure mechanism assumed and the plastic limit analysis predictions are validated by numerical computations based on FEM. For the K0-consolidated ground of clays typically with anisotropic undrained strength property, it is indicated through a parametric study that limit analysis without consideration of anisotropy of soil overestimates the lateral ultimate bearing capacity of a deeply-embedded cylindrical structure in soft ground in a certain condition.

Recent Development of Pressure Vessel Technology in China——Formulation of Chinese Design Code by Analysis

This paper is a summarized account of the Chinese professional stantard—JB4732 Steel Pressure Vessels—Design by Analysis. As compared with similar standards in other countries, there are some features in elastic plastic analysis of pressure vessels and their components in JB4732. Three of them are introduced in brief. It includes: flat head design method considering plastic carrying capactities of structures; a reinforcement design method based on limit analysis of spherical shells with nozzles and the calculation method of stress concentration factors of two intersecting cylindrical shells with d/D≤0 7 based on an analytical solution.

‘All Solid Things Vanish Into Thin Air.’The Space in Modern andLate Modern Plastic Art

The article follows Max Weber's Comprehensive Sociology and uses the hermeneutic and iconological analysis sociological methods applied to plastic works(painting and sculpture),significant and representative of modern and late modern art.Starting from these theoretical and methodological bases,it pursues three specific objectives:to analyze the construction of space in plastic art,to verify how this theme has evolved in artistic practices from the first modernity to the second and to verify the way in which the complementary visual language the conceptual of contemporary sociological theory.In this regard,the analysis and interpretation of the eleven selected works reveals three important consequences of the modern influence on space,gradually emptied of meaning and replaced by non-places:its conversion into merchandise,its loss of solidity and stability and the confusion that occurs in it between reality and its representation.Consequently,the implicit content converges with the essential postulates of the sociologists who have approached the subject of space,although it goes further because the foray into the iconographic hermeneutics of these works puts an image to the conceptual theoretical discourses of the sociologists,inaway that visual language complements and enriches,with more emotional and sensitive nuances Therefore our discipline begins to overcome a traditional deficit,in that it moves from the essential rationality that structures its origin and turns towards a greater coupling of the emotional and sensitive social plane.

Prediction of Forming Limit Diagrams for Materials with HCP Structure

The forming limit diagram（FLD） is an important tool to be used when characterizing the formability of metallic sheets used in metal forming processes. Experimental measurement and determination of the FLD is timeconsuming and therefore the analytical prediction based on theory of plasticity and instability criteria allows a direct and efficient methodology to obtain critical values at different loading paths, thus carrying significant practical importance.However, the accuracy of the plastic instability prediction is strongly dependent on the choice of the material constitutive model [1–3]. Particularly for materials with hexagonal close packed（HCP） crystallographic structure, they have a very limited number of active slip systems at room temperature and demonstrate a strong asymmetry between yielding in tension and compression [4, 5]. Not only the magnitude of the yield locus changes, but also the shape of the yield surface is evolving during the plastic deformation [4]. Conventional phenomenological constitutive models of plasticity fail to capture this unconventional mechanical behavior [4, 6]. Cazacu and Plunkett [6] have proposed generic yield criteria, by using the transformed principal stress, to account for the initial plastic anisotropy and strength differential（SD） effect simultaneously. In this contribution, a generic FLD MATLAB script was developed based on Marciniak–Kuczynski analytical theory and applied to predict the localized necking. The influence of asymmetrical effect on the FLD was evaluated. Several yield functions such as von Mises, Hill, Barlat89, and Cazacu06 were incorporated into analysis. The paper also presents and discusses the influence of different hardening laws on the formability of materials with HCP crystal structures. The findings indicate that the plastic instability theory coupled with Cazacu model can adequately predict the onset of localized necking for HCP materials under different strain paths.

Improvement potential of today＇s WEEE recycling performance： The case of LCD TVs in Belgium

Waste of electrical and electronic equipment （WEEE） constitutes one of the most relevant waste streams because of the quantity and presence of valuable materials. However, there is limited knowledge on the resource potential of urban mining WEEE, as data on material composition, and the efficiency of current recycling treatments are still scarce. In this article, an evaluationof the recycling performance at a national level for one of the fastest growing e-waste streams： LCD TVs is carried out through the following four steps. Firstly, material characterisation is performed by means of sampling of the waste stream. Secondly, a material flow analysis is conducted by evaluating the separation performance of a recycling plant in Belgium..Thirdly, the recovered economic value and avoided environmental impact （EI） of the analysed recycling system is assessed. Finally, the potential of urban mining for Belgium is forecasted. The analysis shows that while recycling performance for ferrous metals and aluminium are relatively high; there is substantial room to better close the material loops for precious metals （PM） and plastics. PMs and plastics account for 66 % of the economic value in LCD TVs and 57% of the El. With the current, commonly applied recycling technology only one-third of the PM and housing plastics are recycled; meaning that for＇these material＇s, at a national level for Belgium, there is a potential for improvement that represents 3.3 million euros in 2016 and 6.8 million euros in 2025.