技术领域Technical Field
本发明涉及智能材料与自适应结构技术领域，尤其涉及一种新型SMA双稳态结构的4D打印方法。The present invention relates to the technical field of smart materials and adaptive structures, and in particular to a 4D printing method for a novel SMA bistable structure.
背景技术Background Art
双稳态结构广泛存在于自然界与人们的日常生活中，如捕蝇草叶片、蠼螋翅膀、生活中的发卡等。同时，作为一种经典的可变形结构，双稳态结构仅需克服临界状态即可实现不同稳态之间的相互切换且变形后结构不需要额外的能量输入即可保持，因此在可展开结构、MEMS器件、软体机器人等诸多领域具有重要的应用价值。但对于传统的双稳态结构，其致动变形往往依赖于手、气泵、马达等提供的外界机械载荷，附加的动力系统限制了双稳态结构的进一步发展和应用。Bistable structures are widely present in nature and people's daily lives, such as Venus flytrap leaves, earwig wings, hairpins in life, etc. At the same time, as a classic deformable structure, the bistable structure only needs to overcome the critical state to achieve the mutual switching between different stable states, and the deformed structure does not require additional energy input to maintain, so it has important application value in many fields such as deployable structures, MEMS devices, and soft robots. However, for traditional bistable structures, their actuation deformation often depends on external mechanical loads provided by hands, air pumps, motors, etc., and the additional power system limits the further development and application of bistable structures.
智能材料及相关技术的发展为双稳态结构提供了新的机遇，使其能够脱离额外动力系统的限制，发生自驱动的主动变形。在多种现有的智能材料之中，形状记忆合金(shapememory alloy，SMA)是一种独特的金属材料，在能量密度、变形输出力、驱动条件等多个方面展现出优于聚合物材料的功能特性，是一种较为易于推广的智能材料。然而在现有的研究案例中，形状记忆合金的应用实际仍局限于传统模式，具体来说，只是将它们制作成具有简单构型(丝、弹簧等)的分立式驱动元件，借助其恢复变形所产生的机械力来触发双稳态元件。如中国发明专利“可重构的双稳态装置”(其公布号为CN103035427A)，将双稳态结构与丝线状SMA致动部件相结合，通过SMA使双稳态结构发生变形。但该发明存在着SMA致动结构与弹性双稳态板相配合的问题，不仅增加了系统的复杂性，更重要的是，形状记忆合金在其中并未发挥核心的功能作用，因而也没有对此类智能结构的驱动方式和性能表现带来真正意义上的改进或提升。The development of smart materials and related technologies has provided new opportunities for bistable structures, enabling them to break away from the constraints of additional power systems and undergo self-driven active deformation. Among the various existing smart materials, shape memory alloy (SMA) is a unique metal material that exhibits functional characteristics superior to polymer materials in terms of energy density, deformation output force, driving conditions, etc., and is a smart material that is relatively easy to promote. However, in existing research cases, the application of shape memory alloys is still limited to traditional models. Specifically, they are only made into discrete driving elements with simple configurations (wires, springs, etc.), and the mechanical force generated by their recovery deformation is used to trigger the bistable element. For example, the Chinese invention patent "Reconfigurable Bistable Device" (whose publication number is CN103035427A) combines a bistable structure with a wire-shaped SMA actuating component, and deforms the bistable structure through SMA. However, this invention has the problem of matching the SMA actuation structure with the elastic bistable plate, which not only increases the complexity of the system, but more importantly, the shape memory alloy does not play a core functional role therein, and thus does not bring any real improvement or enhancement to the driving mode and performance of such intelligent structures.
发明内容Summary of the invention
本发明的目的在于克服上述现有技术的缺点，提供一种SMA双稳态结构的4D打印方法。The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art and provide a 4D printing method for a SMA bistable structure.
为达到上述目的，本发明采用以下技术方案：In order to achieve the above object, the present invention adopts the following technical solutions:
SMA双稳态结构的4D打印方法，包括双稳态本体结构及两侧连接关节，需结合适当的支撑底座和加热激励方式发挥作用；The 4D printing method of the SMA bistable structure, including the bistable main body structure and the connecting joints on both sides, needs to be combined with an appropriate support base and a heating excitation method to work;
所述的双稳态本体结构为无预应力的余弦梁结构，其几何方程为：其中L为跨距，H为拱高。The bistable body structure is a cosine beam structure without prestress, and its geometric equation is: Where L is the span and H is the arch height.
所述的双稳态余弦梁结构的初始形状为一阶屈曲模态形状的上凸构型。The initial shape of the bistable cosine beam structure is a convex configuration of a first-order buckling mode shape.
所述的连接关节为开口内收的矩形卡扣结构。The connecting joint is a rectangular buckle structure with an inward opening.
所述的支撑底座为一个截面为矩形的筒状结构，厚度为3mm，采用树脂材料制造。The support base is a cylindrical structure with a rectangular cross section, a thickness of 3 mm, and is made of resin material.
所述的加热激励方案为柔性电热膜传热方案，通过热传导的方式加热SMA新型双稳态结构。The heating excitation scheme is a flexible electric heating film heat transfer scheme, which heats the SMA novel bistable structure by heat conduction.
作为本发明的进一步改进，所述的双稳态本体结构及两侧连接结构均采用SMA的选择性激光熔融工艺一体化加工成型。As a further improvement of the present invention, the bistable main body structure and the connection structures on both sides are integrally formed by the selective laser melting process of SMA.
作为本发明的进一步改进，所述的双稳态本体结构满足拱高与梁厚之比大于2.31。As a further improvement of the present invention, the bistable body structure satisfies a ratio of arch height to beam thickness greater than 2.31.
作为本发明的进一步改进，所述的SMA双稳态结构满足以下特点：As a further improvement of the present invention, the SMA bistable structure satisfies the following characteristics:
低温下将SMA双稳态结构两侧连接关节固定，在SMA双稳态结构中心位置处施加位移载荷，结构将变形至另一稳定位置(下凹构型)，并在卸载后仍能保持。通过热传导的方式加热SMA双稳态结构，它将恢复至初始形状(上凸构型)。At low temperature, the joints on both sides of the SMA bistable structure are fixed, and a displacement load is applied at the center of the SMA bistable structure. The structure will deform to another stable position (concave configuration) and can still maintain it after unloading. By heating the SMA bistable structure through heat conduction, it will return to its initial shape (convex configuration).
作为优选，本发明中的直流稳压电源为30V、5A电源。Preferably, the DC regulated power supply in the present invention is a 30V, 5A power supply.
与现有技术相比，本发明具有以下有益效果：Compared with the prior art, the present invention has the following beneficial effects:
(1)工艺先进，结构集约性、功能完整性良好。采用选择性激光熔融的增材制造工艺加工SMA功能元件，充分发挥了智能材料和功能特性，使双稳态结构本身即可发生温度驱动下的主动变形，避免了此前研究中智能材料与可变形结构相配合所带来的适应性问题。(1) Advanced technology, good structural intensiveness and functional integrity. The SMA functional components are processed by selective laser melting additive manufacturing process, which gives full play to the smart material and functional characteristics, so that the bistable structure itself can actively deform under temperature drive, avoiding the adaptability problems caused by the combination of smart materials and deformable structures in previous studies.
(2)驱动方式简洁高效。本发明采用柔性电热膜加热SMA双稳态结构，仅需通电/断电即可完成驱动，与传统控制手段相比难度极低，且较好地解决了复杂三维SMA功能结构的加热驱动问题。(2) The driving method is simple and efficient. The present invention uses a flexible electric heating film to heat the SMA bistable structure, which can be driven by simply turning on/off the power. Compared with traditional control methods, it is much easier and better solves the heating and driving problem of complex three-dimensional SMA functional structures.
(3)实现SMA的高速、高能量输出的变形。通常情况下SMA的变形响应速度较慢，而将SMA与双稳态结构相结合，不仅可以大幅提升SMA的变形响应速度，还能降低SMA的驱动条件，为高性能形状记忆合金驱动结构的设计开发提供了思路。(3) Realize high-speed, high-energy output deformation of SMA. Normally, the deformation response speed of SMA is slow. Combining SMA with a bistable structure can not only greatly improve the deformation response speed of SMA, but also reduce the driving conditions of SMA, providing ideas for the design and development of high-performance shape memory alloy driving structures.
(4)良好的应用前景。不同于具有类似功能的聚合物材料，SMA在低温下(奥氏体相变开始温度以下)有很好的柔顺性，而升高温度(奥氏体相变结束温度以上)，材料可产生较大的变形回复力且变形后具有金属材料独特的高刚度和承载能力。因此由SMA构成的自适应结构可作为关键功能元件，可应用于大驱动力、高负载等工程应用场合。(4) Good application prospects. Unlike polymer materials with similar functions, SMA has good flexibility at low temperatures (below the start temperature of austenite phase transformation), and at elevated temperatures (above the end temperature of austenite phase transformation), the material can produce a large deformation recovery force and has the unique high stiffness and load-bearing capacity of metal materials after deformation. Therefore, the adaptive structure composed of SMA can be used as a key functional element and can be applied to engineering applications such as large driving force and high load.
附图说明BRIEF DESCRIPTION OF THE DRAWINGS
图1为本发明中的SMA双稳态结构模型图。FIG. 1 is a diagram of a bistable structure model of an SMA in the present invention.
图2为本发明中的SMA双稳态结构与底座装配后的结构图。FIG. 2 is a structural diagram of the SMA bistable structure and the base after being assembled in the present invention.
图3为本发明实施例中SMA双稳态结构低温下加载、卸载的载荷-位移曲线图。FIG. 3 is a load-displacement curve diagram of the SMA bistable structure under low temperature loading and unloading in an embodiment of the present invention.
图4为本发明实施例中SMA双稳态结构温度变化图。FIG. 4 is a temperature variation diagram of the SMA bistable structure in an embodiment of the present invention.
图5为本发明实施例中SMA双稳态结构位移变化图。FIG. 5 is a diagram showing the displacement variation of the SMA bistable structure in an embodiment of the present invention.
具体实施方式DETAILED DESCRIPTION
为了使本技术领域的人员更好地理解本发明方案，下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明一部分的实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都应当属于本发明保护的范围。In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.
需要说明的是，本发明的说明书和权利要求书及上述附图中的术语“第一”、“第二”等是用于区别类似的对象，而不必用于描述特定的顺序或先后次序。应该理解这样使用的数据在适当情况下可以互换，以便这里描述的本发明的实施例能够以除了在这里图示或描述的那些以外的顺序实施。此外，术语“包括”和“具有”以及他们的任何变形，意图在于覆盖不排他的包含，例如，包含了一系列步骤或单元的过程、方法、系统、产品或设备不必限于清楚地列出的那些步骤或单元，而是可包括没有清楚地列出的或对于这些过程、方法、产品或设备固有的其它步骤或单元。It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.
如图1至2所示，本发明通过4D打印工艺将形状记忆合金的二元金属相态与双稳态结构的二元态相结合，提供一种新型SMA双稳态结构；As shown in FIGS. 1 to 2 , the present invention combines the binary metal phase of the shape memory alloy with the binary state of the bistable structure through a 4D printing process to provide a novel SMA bistable structure;
所述新型SMA双稳态结构，包括双稳态本体结构及两侧连接关节，均采用4D打印一体成型，需结合适当的支撑底座和加热激励方式发挥作用；The novel SMA bistable structure, including the bistable main body structure and the connecting joints on both sides, is integrally formed by 4D printing and needs to be combined with an appropriate support base and a heating excitation method to function;
所述的双稳态本体结构为无预应力的余弦梁结构，其几何方程为：y＝H/2L*(1-cos(2*π/L*x))，其中L为跨距，H为拱高。The bistable main body structure is a cosine beam structure without prestress, and its geometric equation is: y=H/2L*(1-cos(2*π/L*x)), wherein L is the span and H is the arch height.
所述的双稳态余弦梁结构的初始形状为一阶屈曲模态形状的上凸构型。The initial shape of the bistable cosine beam structure is a convex configuration of a first-order buckling mode shape.
所述的连接关节为矩形卡扣结构，且开口略小于与其配合的结构。两侧卡扣结构与支撑结构的具体装配方式为：打印完成后将结构温度冷却至马氏体相变结束温度以下，通过外力将关节开口扩大，使其能够安装在底座凹槽上。在关节安装后保持其与底座的相对位置，对关节进行加热，使其温度升至奥氏体相变结束温度以上，关节将发生形状恢复，而底座凹槽结构将限制其变形，因此梁关节将与底座锁紧。The connection joint is a rectangular buckle structure, and the opening is slightly smaller than the structure that matches it. The specific assembly method of the buckle structures on both sides and the support structure is as follows: after printing is completed, the structure temperature is cooled to below the end temperature of the martensitic phase transformation, and the joint opening is expanded by external force so that it can be installed on the base groove. After the joint is installed, its relative position with the base is maintained, and the joint is heated to a temperature above the end temperature of the austenitic phase transformation. The joint will recover its shape, and the base groove structure will limit its deformation, so that the beam joint will be locked with the base.
所述的支撑底座为一个截面为矩形的筒状结构，厚度为3mm，采用树脂材料制造。The support base is a cylindrical structure with a rectangular cross section, a thickness of 3 mm, and is made of resin material.
所述的加热激励方案为柔性电热膜传热方案，通过热传导的方式加热SMA双稳态结构。The heating excitation scheme is a flexible electric heating film heat transfer scheme, which heats the SMA bistable structure by heat conduction.
SMA新型双稳态结构4D打印过程：SMA new bistable structure 4D printing process:
采用SLM打印设备将Ti-Ni金属粉末逐层扫描成型为双稳态屈曲梁的一个稳态形状。在加工的过程中，Ti-Ni金属粉末在激光的照射下达到熔点被烧结成型，温度远高于奥氏体相变的结束温度(Af)，此时SMA处于奥氏体相；The SLM printing equipment is used to scan Ti-Ni metal powder layer by layer to form a stable shape of a bistable buckled beam. During the processing, the Ti-Ni metal powder reaches the melting point under the irradiation of the laser and is sintered. The temperature is much higher than the end temperature (Af) of the austenite phase transformation. At this time, the SMA is in the austenite phase;
将所打印好的SMA双稳态梁冷却至马氏体相变的结束温度(Mf)以下。此时结构内部金相由奥氏体完全转变为孪晶马氏体，结构宏观形状不变；The printed SMA bistable beam is cooled to below the end temperature (Mf) of the martensitic phase transformation. At this time, the internal metallographic phase of the structure is completely transformed from austenite to twinned martensite, and the macroscopic shape of the structure remains unchanged;
对SMA双稳态梁两侧支撑、中部加载。宏观上SMA双稳态梁将由一个稳态形状变形至另一稳态形状，变形完成后曲梁存在非孪晶马氏体与孪晶马氏体两种金相；The SMA bistable beam is supported on both sides and loaded in the middle. Macroscopically, the SMA bistable beam will deform from one stable shape to another stable shape. After the deformation is completed, the curved beam has two metallographic phases: non-twinned martensite and twinned martensite.
对SMA梁卸载。其宏观结构将发生小幅恢复，并最终停在临界位置。由于非孪晶马氏体不会发生逆相变，因此其内部金相亦不发生改变；Unload the SMA beam. Its macrostructure will recover slightly and eventually stop at the critical position. Since non-twinned martensite will not undergo reverse phase transformation, its internal metallographic phase will not change;
对SMA双稳态梁进行加热。梁上的非孪晶马氏体将转变为奥氏体，相关区域的残余应变消失，同时梁的整体形状也将恢复至加载前的第一稳态形状。When the SMA bistable beam is heated, the non-twinned martensite on the beam will transform into austenite, the residual strain in the relevant area will disappear, and the overall shape of the beam will recover to the first stable state shape before loading.
SMA双稳态结构的安装方法，包括以下步骤：The installation method of the SMA bistable structure comprises the following steps:
用三维建模软件建立新型SMA双稳态结构模型，设置工艺参数，进行选择性激光熔融工艺加工成型。The new SMA bistable structure model was established using 3D modeling software, and the process parameters were set to perform selective laser melting process.
其中，选用的材料为等原子比的镍钛金属粉末。Among them, the selected material is nickel-titanium metal powder with equal atomic ratio.
打印完成后取出模型，并对其进行回火处理。After printing, the model is taken out and tempered.
将结构冷却后通过外力将卡扣开口扩大，使其能够安装在底座上；在关节安装后保持其与底座的相对位置；对关节进行加热锁紧卡扣。After the structure is cooled, the buckle opening is enlarged by external force so that it can be installed on the base; after the joint is installed, its relative position with the base is maintained; the joint is heated to lock the buckle.
将柔性电热膜贴在SMA双稳态结构表面，将电热膜用导线连至直流电源。The flexible electric heating film is attached to the surface of the SMA bistable structure, and the electric heating film is connected to a DC power supply with a wire.
作为优选，本发明中选择性激光熔融的工艺参数为铺粉层厚d＝50μm，搭接率为45％，激光功率P＝75W，激光速度v＝200mm/s，搭接宽度δ＝76.5μm。Preferably, the process parameters of the selective laser melting in the present invention are powder layer thickness d=50 μm, overlap rate 45%, laser power P=75 W, laser speed v=200 mm/s, overlap width δ=76.5 μm.
作为优选，本发明中回火处理的方式为：在热处理炉中将温度从室温缓慢提高到550℃，升温速率为10℃/min，在此温度保持30min后随炉冷却至室温。Preferably, the tempering treatment method in the present invention is: slowly increase the temperature from room temperature to 550°C in a heat treatment furnace at a heating rate of 10°C/min, maintain this temperature for 30 minutes, and then cool to room temperature with the furnace.
以下通过具体实施例对本发明进行详细说明：The present invention is described in detail below through specific embodiments:
实施例1Example 1
实施例中选取的结构参数为：L＝40mm，H＝5mm，d＝0.5mm，w＝3mm，m＝4mm，n＝4mm。The structural parameters selected in the embodiment are: L=40 mm, H=5 mm, d=0.5 mm, w=3 mm, m=4 mm, n=4 mm.
采用有限元仿真软件ABAQUS对SMA双稳态结构的变形特性进行仿真，在ABAQUS中引入SMA的Ben Jaber本构模型UMAT子程序。The finite element simulation software ABAQUS is used to simulate the deformation characteristics of the SMA bistable structure, and the Ben Jaber constitutive model UMAT subroutine of SMA is introduced into ABAQUS.
每次迭代步计算前，通过提供前一次迭代步计算中材料的应变张量、应力张量、温度、以及它们的增量等参数，子程序就会为当前迭代步计算出新的参数。这相当于对于每步迭代，UMAT子程序均会更新材料参数并带入计算。首先在温度恒定，且低于马氏体向奥氏体相变初始温度的条件下对结构进行加载与卸载仿真，仿真结果如图3所示。Before each iteration, the subroutine will calculate new parameters for the current iteration by providing the material strain tensor, stress tensor, temperature, and their increments in the previous iteration. This is equivalent to the UMAT subroutine updating the material parameters and bringing them into the calculation for each iteration. First, the structure is loaded and unloaded under the condition of constant temperature and lower than the initial temperature of the martensite to austenite phase transformation. The simulation results are shown in Figure 3.
SMA双稳态结构加载过程具有明显的单稳态特征，但卸载过程中并不会像单稳态结构一样自发的回到原点，而是会稳定地停留在某个临界位置(图3中的c点，与最大变形位置的距离为1.46mm)，若在该位置处施加载荷使其越过临界区域(卸载曲线c点与d点之间的部分)，SMA梁又将主动发生变形。整体来看，低温下SMA屈曲梁仍具备类似于双稳态结构的稳态特征和能量势垒，故此处将其定义为类双稳态结构。The SMA bistable structure has obvious monostable characteristics during loading, but it will not spontaneously return to the origin like a monostable structure during unloading, but will stay stably at a critical position (point c in Figure 3, 1.46mm away from the maximum deformation position). If a load is applied at this position to make it cross the critical area (the part between points c and d of the unloading curve), the SMA beam will actively deform again. Overall, the SMA buckled beam at low temperature still has stable characteristics and energy barriers similar to the bistable structure, so it is defined as a quasi-bistable structure here.
其次，在第一个时间步加载后去除载荷，同时前两个时间步温度低于马氏体向奥氏体相变初始温度，第三个时间步温度逐渐升至马氏体向奥氏体相变结束温度以上的条件下，SAM双稳态结构的温度变化、中心点处的位移变化如图4、图5所示。Secondly, the load is removed after loading in the first time step. At the same time, under the conditions that the temperature in the first two time steps is lower than the initial temperature of the martensite to austenite phase transformation, and the temperature in the third time step gradually rises to above the end temperature of the martensite to austenite phase transformation, the temperature change and displacement change at the center point of the SAM bistable structure are shown in Figures 4 and 5.
可以看出加热过程中SMA双稳态结构可自行恢复至其初始位置，且恢复过程中梁中心位置处的位移均存在跳跃式变化。在其中心位置在短时间内产生了7.68mm的位移。It can be seen that the SMA bistable structure can recover to its initial position by itself during the heating process, and the displacement at the center of the beam changes in a jump-like manner during the recovery process. A displacement of 7.68 mm is generated at its center in a short period of time.
在变形的驱动特性方面，以SMA屈曲梁跳变完成后的温度作为触发温度(在图中已用红点标出)。仿真结果表明，拱高为5mm的屈曲梁结构的触发温度为332.7K，明显低于SMA奥氏体相变的结束温度(360K)。In terms of the deformation driving characteristics, the temperature after the SMA buckled beam jump is completed is used as the trigger temperature (marked with a red dot in the figure). The simulation results show that the trigger temperature of the buckled beam structure with an arch height of 5mm is 332.7K, which is significantly lower than the end temperature of the SMA austenite phase transformation (360K).
此处的仿真结果表明，SMA双稳态结构的功能特性可满足要求。The simulation results here show that the functional characteristics of the SMA bistable structure can meet the requirements.
在此基础上借助SLM打印设备将Ti-Ni粉末逐层扫描成型，并将其安装在底座上。On this basis, the Ti-Ni powder is scanned and formed layer by layer with the help of SLM printing equipment and installed on the base.
选用的打印原材料为粉末状的Ti-Ni合金，原子比为Ti:Ni＝1:1，其中Ti原子和Ni原子的质量分数分别为42.68％与57.36％。粉末粒度为15-53μm，球形度为0.89。The raw material used for printing is powdered Ti-Ni alloy with an atomic ratio of Ti:Ni=1:1, where the mass fractions of Ti atoms and Ni atoms are 42.68% and 57.36% respectively. The powder particle size is 15-53μm and the sphericity is 0.89.
选用工艺参数为：铺粉层厚d＝50μm，搭接率为45％，激光功率P＝75W，激光速度v＝200mm/s，搭接宽度δ＝76.5μm。The selected process parameters are: powder layer thickness d = 50 μm, overlap rate 45%, laser power P = 75 W, laser speed v = 200 mm/s, overlap width δ = 76.5 μm.
对SMA双稳态结构进行动态测试，结果表明曲梁完全变形仅用时60毫秒(前40毫秒发生小幅变形，后20毫秒发生大变形)。这表明双稳态结构的跳变变形可以大幅提升SMA的变形速度，使其在相当短的时间内(毫秒级)即可实现完整的形状恢复，相比与此前的SMA功能结构具有较大的性能优势。The dynamic test of the SMA bistable structure showed that it only took 60 milliseconds for the curved beam to fully deform (a small deformation occurred in the first 40 milliseconds and a large deformation occurred in the last 20 milliseconds). This shows that the jump deformation of the bistable structure can greatly increase the deformation speed of the SMA, allowing it to achieve complete shape recovery in a very short time (milliseconds), which has a greater performance advantage over the previous SMA functional structure.
重量仅为0.64g的SMA屈曲梁(包含两侧连接结构)变形可推动20g的砝码高度提升21mm，产生4.12mJ的输出功(68.7mW的输出功率)。经计算，其功率密度高达779.4kW/m3。The deformation of the SMA buckling beam (including the connecting structure on both sides) weighing only 0.64g can push the 20g weight to increase its height by 21mm, generating an output work of 4.12mJ (output power of 68.7mW). According to calculations, its power density is as high as 779.4kW/m3 .
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| CN202410640881.7ACN118595456A (en) | 2024-05-22 | 2024-05-22 | A 4D printing method for SMA bistable structure |
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| Publication | Publication Date | Title |
|---|---|---|
| Yao et al. | 4D printing and collaborative design of highly flexible shape memory alloy structures: a case study for a metallic robot prototype | |
| Mavroidis | Development of advanced actuators using shape memory alloys and electrorheological fluids | |
| Rao et al. | Design of shape memory alloy (SMA) actuators | |
| JP5694144B2 (en) | Shape-changing structural member with embedded spring | |
| Tan et al. | Dynamic snap-through instability and damped oscillation of a flat arch of hard magneto-active elastomers | |
| Suzuki et al. | Displacement control of an antagonistic-type twisted and coiled polymer actuator | |
| Suzuki et al. | Control of twisted and coiled polymer actuator with anti-windup compensator | |
| Song et al. | Application of shape memory alloy wire actuator for precision position control of a composite beam | |
| Wanhill et al. | Shape memory alloys (SMAs) for aerospace applications | |
| Li et al. | A fast actuated soft gripper based on shape memory alloy wires | |
| Mizzi et al. | Design of shape memory alloy sandwich actuators: an analytical and numerical modelling approach | |
| CN118595456A (en) | A 4D printing method for SMA bistable structure | |
| Battaglia et al. | Advanced material thermomechanical modelling of shape memory alloys applied to automotive design | |
| Karakalas et al. | Effect of tension-compression asymmetry and partial transformation on the response of shape memory alloy beam structures | |
| Karunakaran et al. | Heating techniques of shape memory alloy (sma)-a review | |
| CN105164410A (en) | Thermoelectric generator | |
| Sofla et al. | An antagonistic flexural unit cell for design of shape morphing structures | |
| Rim et al. | Development of a shape memory alloy wire actuator to operate a morphing wing | |
| Karakalas et al. | Preliminary design and numerical investigation of sma torsion tubes for the actuation of articulated adaptive panels | |
| Luji et al. | Heating and cooling mechanisms for SMA actuator-a brief review | |
| Li et al. | Design of heat-activated reversible integral attachments for product-embedded disassembly | |
| Schick et al. | Incorporation of shape memory alloy actuators into morphing aerostructures | |
| Tao et al. | Design and Snap-Through Behaviors of Shape Memory Polymer Based Multistable Mesh Structure | |
| Lederlé | Issues in the design of shape memory alloy actuators | |
| Jovanova et al. | Modeling and prototyping of self-folding origami structure |
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