建构的织理性中对建筑表皮的生态功能性研究

将表皮单纯地看成是风格的模仿、符号的拼贴、图像的游戏,这无疑是哗众取宠,完全失去了建筑设计中最为重要的理性思维。东西方建筑在各自的建造体系中都有一套完整的建构的织理性逻辑--出于对空间使用功能的合理思考,从建筑表皮的材料性和功能性出发,进而表现其本体的属性,包括材料性能、生态性能及基本的美学性能,以这些性能为出发点设计和建造出来的表皮才符合建构中的织理性。

浅析赖特织理性建构思想

在众多关于赖特建筑作品的学术研究中,对其织理性建构及其后世影响的研究不足。森佩尔建筑四要素中的围合通过编织方法形成,这直接或间接影响到赖特建筑中蕴含的织理性建构意味。文章从赖特与三种文化——日本文化、德国文化、伊斯兰文化的关系出发,佐证赖特与森佩尔理论之间的渊源。其后对赖特织理性建构进行分类分析,通过材料分类得出赖特织理性建构分为木材、混凝土、玻璃材质的三种织理,并解释并分析了其具体处理方法和影响。织理性建构这个建筑观念给后世带来深远的影响,亦对现代建筑如何融合中国传统建筑文化提供了新的方向。

数字化手段下几种织理形态设计方式研究

依据织理形式发展演变的规律,分析编织这类特殊形态在建筑设计中的运用,同时阐述在当代数字化设计影响下的编织形式的结构特点与逻辑形式,最后对相关类型的织理性设计手法进行分类讨论。研究基于参数化平台,将织理分作基本面织理、空间拓扑织理、单元式织理三个大类分别进行设计实践,得出三种在数字化手段下织理形式的具体设计手段与建造方法。研究表明织理形式经过数字演变后已经不仅仅是简单的图形堆叠,其多变的交织模式、动态的离散单元、优化的力学特性都表明数字织理的独特优势。同时将这种设计方式类比于建筑实践中,以此扩大对建筑具体结构如墙、柱等部件的探讨。

Effect of thermo-mechanical treatment on microstructure and mechanical properties of wire-arc additively manufactured Al-Cu alloy

Wire-arc additive manufacture(WAAM)has great potential for manufacturing of Al-Cu components.However,inferior mechanical properties of WAAM deposited material restrict its industrial application.Inter-layer cold rolling and thermo-mechanical heat treatment(T8)with pre-stretching deformation between solution and aging treatment were adopted in this study.Their effects on hardness,mechanical properties and microstructure were analyzed and compared to the conventional heat treatment(T6).The results show that cold rolling increases the hardness and strengths,which further increase with T8 treatment.The ultimate tensile strength(UTS)of 513 MPa and yield stress(YS)of 413 MPa can be obtained in the inter-layer cold-rolled sample with T8 treatment,which is much higher than that in the as-deposited samples.The cold-rolled samples show higher elongation than that of as-deposited ones due to significant elimination of porosity in cold rolling;while both the T6 and T8 treatments decrease the elongation.The cold rolling and pre-stretching deformation both contribute to the formation of dense and dispersive precipitatedθ′phases,which inhibits the dislocation movement and enhances the strengths;as a result,T8 treatment shows better strengthening effect than the T6 treatment.The strengthening mechanism was analyzed and it was mainly related to work hardening and precipitation strengthening.

Effect of cold rolling deformation on microstructure evolution and mechanical properties of spray formed Al−Zn−Mg−Cu−Cr alloys

The impact of cold rolling deformation,which was introduced after solid solution and before aging treatment,on microstructure evolution and mechanical properties of the as-extruded spray formed Al−9.8Zn−2.3Mg−1.73Cu−0.13Cr(wt.%)alloy,was investigated.SEM,TEM,and EBSD were used to analyze the microstructures,and tensile tests were conducted to assess mechanical properties.The results indicate that the D1-T6 sample,subjected to 25%cold rolling deformation,exhibits finer grains(3.35μm)compared to the D0-T6 sample(grain size of 4.23μm)without cold rolling.Cold rolling refines the grains that grow in solution treatment.Due to the combined effects of finer and more dispersed precipitates,higher dislocation density and smaller grains,the yield strength and ultimate tensile strength of the D1-T6 sample can reach 663 and 737 MPa,respectively.In comparison to the as-extruded and D0-T6 samples,the yield strength of the D1-T6 sample increases by 415 and 92 MPa,respectively.

Effects of ultrasonic treatment on microstructure and mechanical properties of Mg-5Zn-2Er alloy

The effects of ultrasonic treatment on the microstructure and mechanical properties of Mg-5Zn-2Er alloy at room temperature （RT） and high temperature （HT） were investigated. The microstructure and mechanical properties of the samples were studied by OM, SEM and MTS material tester. The results show that the microstructure and mechanical properties are improved after the ultrasonic vibration. The best effects of ultrasonic vibration on microstructure and mechanical properties were obtained with the ultrasonic vibration power of 600 W and time of 100 s. The cavitation and acoustic streaming caused by ultrasonic treatment play a major role in refining the microstructure and increasing mechanical properties of the alloy.

Influence of Zr content on microstructure and mechanical properties of implant Ti-35Nb-4Sn-6Mo-xZr alloys

The influence of Zr content on the microstructure and mechanical properties of implant Ti-35Nb-4Sn-6Mo-xZr （x=0, 3, 6, 9, 12, 15; mass fraction） alloys was investigated. It is shown that Ti-35Nb-4Sn-6Mo-xZr alloys appear to have equiaxed single β microstructure after solution treatment at 1023 K. It is found that the grains are refined first and then coarsened with the increase of Zr content. It is also found that Zr element added to titanium alloys has both the solution strengthening and fine-grain strengthening effect, and affects the lattice parameters. With increasing the Zr content of the alloys, the strength increases, the elongation decreases, whereas the elastic modulus firstly increases and then decreases. The mechanical properties of Ti-35Nb-4Sn-6Mo-9Zr alloy are as follows： σb=785 MPa, δ=11%, E=68 GPa, which is more suitable for acting as human implant materials compared to the traditional implant Ti-6Al-4V alloy.

Microstructure and texture characterization of superplastic Al-Mg-Li alloy

A novel thermomechanical processing was developed for producing fine grained Al-Mg-Li alloy sheets. The influences of static recrystallization annealing on the grain structure and superplastic behavior were investigated. The results show that the refined microstructure has a variation in the distribution of grain size, shape and texture across the normal direction of the sheet. The surface layer （SL） has fine, nearly equiaxed grains with a rotated cUbeND {001 }（310） orientation, whereas the center layer （CL） has coarse, elongated grains with a portion of a fiber orientation. Increasing static recrystallized temperature results in grain growth in the full thickness, decreasing of grain aspect ratio in the center layer, texture sharpening in the surface layer, but weakening in the center layer as well as decreasing of superplastic elongation. Increasing the annealing temperature also produces an sharpening of the rotated cube {001}（310） component and a decreasing of the a fiber texture in the full thickness of the sheet. The formation mechanisms of recrystallization texture at various temperatures and layers were discussed.

Microstructure and mechanical properties of TC21 titanium alloy after heat treatment

Microstructure evolutions during different heat treatments and influence of microstmcture on mechanical properties of TC21 titanium alloy were investigated. The results indicate that the excellent mechanical properties can be obtained by adopting air cooling after forging followed by heat treatment of （900℃, 1 h, AC）＋（590 ℃, 4 h, AC）. Deformation in single β field produces pan-like prior fl grains, while annealing in single fl field produces equiaxed prior fl grains. Cooling rate after forging or annealing in single fl field and the subsequent annealing on the top of α＋β field determine the content and morphology of coarse a plates. During aging or the third annealing, fine secondary a plates precipitate. Both ultimate strength and yield strength decrease with the content increase of coarse a plates. Decreasing effective slip length and high crack propagation resistance increase the plasticity. The crisscross coarse a plates with large thickness are helpful to enhance the fracture toughness.

Microstructure characterization and mechanical properties of TC4-DT titanium alloy after thermomechanical treatment

Influence of thermomechanical treatments （mill annealing, duplex annealing, solution treatment plus aging and triple annealing） on microstructures and mechanical properties of TC4-DT titanium alloy was investigated. Results showed that thermomechanical treatments had a significant influence on the microstructure parameters and higher annealing and aging temperature and lower cooling rate led to the decrease of the volume fraction of primaryαand the size of prior-βand the increase of the width of grain boundary αand secondary α. The highest strength was obtained by solution treatment and aging due to a large amount of transformedβand finer grain boundaryαand secondaryαat the expense of slight decrease of elongation and the ultimate strength, yield strength, elongation, reduction of area were 1100 MPa, 1030 MPa, 13%and 53%separately. A good combination of strength and ductility has been obtained by duplex annealing with the above values 940 MPa, 887.5 MPa, 15%and 51%respectively. Analysis between microstructure parameters and tensile properties showed that with the volume fraction of transformedβphase and the prior-βgrain size increasing, the ultimate strength, yield strength and reduction of area increased, but the elongation decreased. While the width of grain boundary α and secondary α showed a contrary effect on the tensile properties. Elimination of grain boundaryαas well as small prior-βgrain size can also improve ductility.

Microstructure and mechanical properties of heat-treated Ti-5Al-2Sn-2Zr-4Mo-4Cr

The effects of heat treatment parameters on the microstructure,and mechanical properties and fractured morphology of Ti-5Al-2Sn-2Zr-4Mo-4Cr with the equiaxed,bi-modal and Widmanst？tten microstructures were investigated.The heating temperatures for obtaining the equiaxed,bi-modal and Widmanst？tten microstructures were 830,890 and 920 °C,respectively,followed by furnace cooling at a holding time of 30 min.The volume fraction of primary α phase decreased with increasing the heating temperature,which was 45.8% at 830 °C,and decreased to 15.5% at 890 °C,and then the primary α phase disappeared at 920 °C during furnace cooling.The variation of volume fraction of primary α phase in air cooling is similar to that in furnace cooling.The increase in heating temperature and furnace cooling benefited the precipitation and growth of the secondary α phase.The equiaxed microstructure exhibited excellent mechanical properties,in which the ultimate strength,yield strength,elongation and reduction in area were 1035 MPa,1011 MPa,20.8% and 58.7%,respectively.The yield strength and elongation for the bi-modal microstructure were slightly lower than those of the equiaxed microstructure.The Widmanst？tten microstructure exhibited poor ductility and low yield strength,while the ultimate strength reached 1078 MPa.The dimple fractured mechanism for the equiaxed and bi-modal microstructures proved excellent ductility.The coexistence of dimple and intercrystalline fractured mechanisms for the Widmanst？tten microstructure resulted in the poor ductility.

Effects of solution treatment on microstructure and mechanical properties of Al-9.0Zn-2.8Mg-2.5Cu-0.12Zr-0.03Sc alloy

Effects of additions minor contents of 0.03%Sc and 0.12%Zr and solution treatment on microstructure and mechanical properties of Al-9.0Zn-2.8Mg-2.5Cu alloy were studied by metallographic microscopy, differential thermal analysis （DSC） and transmission electron microscopy （TEM）, in order to obtain high-performance Al alloys. The minor additions of Sc （less than 0.1%） were carried out. The results show that with the additions of 0.03% Sc and 0.12% Zr, the petaloid Al3（Sc,Zr） precipitated phases occur in Al-9.0Zn-2.8Mg-2.5Cu alloy, and Al3（Sc,Zr） particles obviously hinder the recrystallization of Al-9.0Zn-2.8Mg-2.5Cu alloy during homogenizing and extruding processes due to their strong pinning effect on dislocation. Multi-stage solution is better than single solution, for it can avoid recrystallization of Al-9.0Zn-2.8Mg-2.5Cu alloy with the minor contents of Sc （less than 0.1%）. The proper solution treatment is （420 °C, 3 h）＋（465 °C, 2 h） under which Al-9.0Zn-2.8Mg-2.5Cu-0.12Zr-0.03Sc alloy obtains a tensile strength of 777.29 MPa and a elongation of 11.84%.

Effects of heat treatment on microstructure and mechanical properties of Mg-3Sn-1Mn magnesium alloy

The effects of heat treatment on the microstructure and mechanical properties of Mg-3Sn-1Mn alloy were preliminarily investigated by using optical and electron microscopy,X-ray diffraction（XRD） analysis,and tensile and creep test.The results indicate that the heat treatment has an obvious effect on the microstructure and mechanical properties of the Mg-3Sn-1Mn alloy.After the solid solution treatment at 420 ℃,a majority of the Mg2Sn phases in the alloy are dissolved into the matrix.However,after the further aging treatment at 250 ℃,lots of fine Mg2Sn phases in the aged alloy are precipitated at the grain boundaries and within the grains.As a result,the tensile and creep properties of the aged alloy are significantly improved.The mechanism for the higher tensile and creep properties of the aged alloy is related to the dispersive distribution of the Mg2Sn phase in the--Mg matrix.

建造的工法 关于“富春山馆”外墙砌筑技艺的探讨和实践

"富春山馆"是业余建筑工作室于2017年完成的一个代表作品,文章从工法的角度对作品的建造过程展开讨论,特别聚焦于其中所采用的带有地域性特点的传统砌筑工艺如何同现代建造技术相结合,进而指出工法的研究产生于真实的建造过程,是劳作性与真实性的统一。以工法的角度展开研究性的思辨,使我们能够回到建造的内在逻辑,回到材料、做法、工艺、构造、节点等具体问题中去展开讨论,从而避开当下建筑界由外在表现主宰的陷阱。

Effects of ultrasonic treatment on microstructure and mechanical properties of Mg-6Zn-0.5Y-2Sn alloy

The effects of the ultrasonic treatment on the microstructure and mechanical properties of Mg-6Zn-0.5Y-2Sn alloy were investigated. The results show that the ultrasonic treatment has significant effect on the microstructure and mechanical properties of Mg-6Zn-0.5Y-2Sn alloy. The phases in Mg-6Zn-0.5Y-2Sn alloy are α-Mg, MgZn2, MgSnY, Mg2Sn, and a small amount of I-phase. With the application of ultrasonic treatment, I-phase nearly disappears, and with increasing the ultrasonic treatment power, the coarse dendrites gradually change into roundish equiaxed grains. The second phases at the α-Mg boundaries transform from coarse, semicontinuous and non-uniform to fine, discontinuous, uniform and dispersive. When the ultrasonic treatment power is 700 W, the best comprehensive mechanical properties of Mg-6Zn-0.5Y-2Sn alloy are obtained. Compared with the untreated alloy, the 0.2%tensile yield strength, ultimate tensile strength and elongation are improved by 28%, 30%and 67%, respectively.

Effects of deep cryogenic treatment on microstructure and properties of WC-11Co cemented carbides with various carbon contents

The effects of deep cryogenic treatment on the microstructure and properties of WC-11 Co cemented carbides with various carbon contents were investigated.The results show that after deep cryogenic treatment,WC grains are refined into triangular prism with sound edges via the process of spheroidization,but WC grain size has no evident change compared with that of untreated alloys.The phase transformation of Co phase from α-Co（FCC） to ε-Co（HCP） is observed in the cryogenically treated alloys,which is attributed to the decrease of W solubility in the binder（Co）.Deep cryogenic treatment enhances the hardness and bending strength of the alloys,while it has no significant effects on the density and cobalt magnetic performance.

Microstructures and mechanical properties of as-extruded and heat treated Mg-6Zn-1Mn-4Sn-1.5Nd alloy

The microstructures and mechanical properties of Mg-6Zn-1Mn-4Sn-1.5Nd alloy subjected to extrusion and T5 treatment were investigated using optical microscopy（OM）, X-ray diffractometer（XRD）, scanning electron microscopy（SEM）, electron back scattered diffraction（EBSD）, transmission electron microscopy（TEM）, hardness tests and uniaxial tensile tests. The results showed that the as-cast alloy consisted of α（Mg）, Mn, Mg7Zn3, Mg2 Sn and Mg Sn Nd phases. Dynamic recrystallization has completed during the extrusion process and the average grain size was 7.2 μm. After T5 treatment, the strength increased obviously, the yield strength and ultimate tensile strength of as-extruded alloy were increased by 94 and 34 MPa, respectively. Microstructure characterization revealed that the improvement of strength was determined by the high number density of β′1 rods.

Effect of heat treatment on microstructure and tensile properties of A356 alloys

Two heat treatments of A356 alloys with combined addition of rare earth and strontium were conducted.T6 treatment is a long time treatment（solution at 535 ℃ for 4 h ＋ aging at 150 ℃ for 15 h）.The other treatment is a short time treatment（solution at 550 ℃ for 2 h ＋ aging at 170 ℃ for 2 h）.The effects of heat treatment on microstructure and tensile properties of the Al-7%Si-0.3%Mg alloys were investigated by optical microscopy,scanning electronic microscopy and tension test.It is found that a 2 h solution at 550 ℃ is sufficient to make homogenization and saturation of magnesium and silicon in α（Al） phase,spheroid of eutectic Si phase.Followed by solution,a 2 h artificial aging at 170 ℃ is almost enough to produce hardening precipitates.Those samples treated with T6 achieve the maximum tensile strength and fracture elongation.With short time treatment（ST）,samples can reach 90% of the maximum yield strength,95% of the maximum strength,and 80% of the maximum elongation.

Effect of heat treatment on microstructures and mechanical properties of sand-cast Mg-10Gd-3Y-0.5Zr magnesium alloy

The microstructure, mechanical properties and fracture behavior of sand-cast Mg-10Gd-3Y-0.5Zr alloy （mass fraction,%） under T6 condition （air cooling after solid solution and then aging heat treatment） were investigated. The optimum T6 heat treatments for sand-cast Mg-10Gd-3Y-0.5Zr alloy are （525 ℃, 12 h＋225 ℃, 14 h） and （525 ℃, 12 h＋250 ℃, 12 h） according to age hardening curve and mechanical properties, respectively. The ultimate tensile strength, yield strength and elongation of the Mg-10Gd-3Y-0.5Zr alloy treated by the two optimum T6 processes are 339.9 MPa, 251.6 MPa, 1.5%and 359.6 MPa, 247.3 MPa, 2.7%, respectively. The tensile fracture mode of peak-aged Mg-10Gd-3Y-0.5Zr alloy is transgranular quasi-cleavage fracture.

Tensile properties and microstructure of Ti14 alloy after semi-solid forging

Tensile properties of a new α＋Ti2Cu alloy after solid forging at 950 °C and semi-solid forging at 1 000 °C and 1 050 °C were investigated over the temperature range of 20-600 °C. The results reveal that high strength and low ductility are obtained in all semi-solid forged alloys. Tensile properties decrease as the semi-solid forging temperature increases, and cleavage fractures are observed after semi-solid forging at 1 050 °C. The variations in tensile properties are attributed to the coarse microstructures obtained in the semi-solid alloys. It is found that the elevated semi-solid temperatures lead to more liquid precipitates along the prior grain boundaries, which increases the peritectic precipitation and formation of Ti2Cu precipitation zones during re-solidification. Recrystallization heat treatment leads to fine microstructure of semi-solid forged alloys, resulting in improvement of tensile properties.