阅读说明：本技术 一种4d打印折叠空间结构智能建造方法 (Intelligent construction method for 4D printing folding space structure ) 是由 王海龙 吴振楠 孙晓燕 王冠楠 侯明欣 于 2021-07-01 设计创作，主要内容包括：本发明公开了一种4D打印折叠空间结构智能建造方法：根据结构功能需求和服役标准确定高强建筑材料和形状记忆材料,确定正常使用状态空间结构造型,对结构框架进行空间优化与力学分析；结合功能要求确定使用工况,设计不同结构折叠状态并确定空间定位关键节点形态、数量和转动变形参数；根据空间框架结构受力和折叠过程需求确定形状记忆材料的空间节点形态和质量分配；以高强建筑材料增材制造空间框架,以形状记忆材料增材制造节点,与轻质膜材料按初始状态组合制造；根据结构不同折叠设计状态控制分步骤变形,实现自适应智能建造。该方法可适用于环境恶劣地区的建筑施工、更高效率建造建筑结构和最大化使用材料的力学性能,变形性能。(The invention discloses an intelligent construction method of a 4D printing folding space structure, which comprises the following steps: determining a high-strength building material and a shape memory material according to the structural functional requirement and the service standard, determining the spatial structure shape in the normal use state, and performing spatial optimization and mechanical analysis on the structural frame; determining a use working condition by combining with functional requirements, designing folded states of different structures, and determining the shape, the number and the rotation deformation parameters of the spatial positioning key nodes; determining the space node shape and mass distribution of the shape memory material according to the stress of the space frame structure and the requirement of the folding process; manufacturing a space frame by using a high-strength building material additive, manufacturing a node by using a shape memory material additive, and manufacturing the node and a light film material according to an initial state; and controlling the deformation in steps according to different folding design states of the structure, thereby realizing self-adaptive intelligent construction. The method can be suitable for building construction in areas with severe environment, building a building structure with higher efficiency and maximizing the mechanical property and the deformation property of materials.)

1. A4D printing folding space structure intelligent construction method is characterized by comprising the following steps:

(1) determining a high-strength building material and a shape memory material according to the structural functional requirement and the service standard, determining the spatial structure shape in the normal use state, and performing spatial optimization and mechanical analysis on the structural frame;

(2) determining a use working condition according to functional requirements, designing different structural folding states, and determining the shape, the number and the rotation deformation parameters of the spatial positioning key nodes according to the different structural folding states;

(3) determining the space node shape and the mass distribution of the shape memory material according to the stress of the space frame structure and the requirement of the folding process, and determining the geometric models of the high-strength steel fixing member and the rotating member;

(4) manufacturing a space frame by using a high-strength building material additive according to a digital design model by adopting 3D printing, manufacturing a node by using a shape memory material additive, and manufacturing the node and a light film material according to an initial state in a combined manner;

(5) and controlling the deformation in steps according to different folding design states of the structure, thereby realizing self-adaptive intelligent construction.

2. The intelligent building method for the 4D printing folding space structure according to claim 1, wherein the shape memory material is selected from shape memory alloy, shape memory polymer, shape memory ceramic or shape memory polymer material.

3. The intelligent building method for the 4D printing folding spatial structure according to claim 1, wherein the high-strength building material is selected from metal, fiber composite material or polymer material.

4. The intelligent building method for the 4D printing folding spatial structure according to claim 1, wherein the light film material is one or more of glass fiber and PTFE (polytetrafluoroethylene) dispersion resin film, polyester surface layer PVC (polyvinyl chloride) film material or polyester film ETFE (ethylene-tetra-ethyl-ethylene) material.

5. The intelligent construction method of the 4D printing folding space structure according to claim 1, characterized in that in the step (5), the excitation information is programmed according to different folding design states of the structure, and the step deformation is controlled by an electric signal to realize the adaptive intelligent construction.

6. The intelligent construction method of the 4D printing folding space structure according to claim 1, wherein in the step (5), the shape and quality light perception of each node are designed according to different folding design states of the structure to be deformed in different steps, so that the structure is automatically opened in a natural light state and automatically folded in a non-light state, and self-adaptive intelligent construction is realized.

Technical Field

The invention relates to the technical fields of digital design, signal control, additive manufacturing, intelligent construction, space structures and the like, in particular to an intelligent construction method of a 4D printing folding space structure.

Background

The 3D printing technology can be used for rapid forming and additive manufacturing, and is rapidly and widely popularized in various industries. 3D prints building can be by computer control realization space design of modelling wantonly, combines together structure atress and building aesthetics, can effectively reduce building rubbish simultaneously, promotes the efficiency of construction, and the reduction of erection time reduces the manual work, promotes mechanized level, reduces the energy consumption on the whole, helps the environment to improve, consequently is a development direction of very potential. In 1 month 2013, 3D printing concrete is adopted by the Netherlands to build a Mobius annular house, and the European space administration in 1 month the same year develops and utilizes the construction technology of 3D printing space stations of lunar soil and other materials. In 2013, 1 month, the Chinese Hui Chuang company completed printing of the temporary building. In 2015, China printed a small multi-story building structure in Suzhou. Current 3D prints structural style and is limited to the material performance, mostly is small-size civil buildings structure accessory or architectural decoration. 4D printing, adding time dimension on the basis of 3D space construction, and automatically implementing 3D space construction design structure technology. In 2013, in 2 months, MIT (institute of technology and technology) of Massachusetts and Stratasys education and research departments in America collaboratively develop a revolutionary new technology capable of forming materials into products quickly, automatically and in a time-varying manner. In 2014, Tibbits, usa developed a material that could be automatically folded into a box. With the success of 4D printing in the laboratory, revolutionary changes will be made to the construction and manufacturing industries.

The 4D printing is an application technology based on intelligent materials with shape memory effect, and the product manufacturing or the structure building is realized by changing the dynamic or static technical parameters of the materials such as shape, position, strain, hardness, frequency, shock resistance, friction and the like through external stimuli such as heat, chemistry, machinery, light, magnetism, electricity and the like. As shown in fig. 1, the shape memory material mainly includes alloy, high molecular polymer, ceramic, etc., and can be classified into thermotropic type, electroluminescence type, photoinduced type, chemical induction type, etc., according to the shape recovery principle, and can be made into various forms of films, fibers, silk threads, particles, etc., or can be combined with other materials to be made into composite materials, and can be used for manufacturing hinge structures, temperature control devices, biological monitoring, daily equipment, light control circuits, aviation facilities, etc., and has wide application prospects. Although 4D printing technology is well-established in the scientific research field, it is still in the beginning of the patent application. At present, few patent applications related to 4D printing technology at home and abroad are available, and the application direction mainly focuses on the preparation of composite materials and the technical application. Taiwan TWM483189U discloses a four-dimensional printing substrate, the volume of which can be changed with the temperature and humidity, and the size, shape and depth of the corresponding dents, and the layout of the dents are also changed. China CN104116578B prints and forms artificial blood vessel stent through 4D, and this kind of stent adopts shape memory polymer as raw materials, need not the expansion (or adopt less expansion force) when implanting the human body and can reach the assigned position, takes place self-deformation such as bending, distortion, inflation after that under the excitation of external field and finally reaches preset three-dimensional space configuration, with the inseparable stable laminating of blood vessel inner wall, reduces the strong impact of expansion process to the vascular wall, reduces the vascular wall and tears the risk. CN106738875A discloses a 4D printing method, which can design and print a geometric model of active and passive materials in a molding member, thereby realizing curvature change of a programmable control material. CN105602213B discloses a memory micro-nano composite material. In 2017, the first world computer-aided 4D printing breast reconstruction was completed by the Cijing Hospital, the fourth military medical university, China. After the breast cancer patient is subjected to large-scale breast resection, a pre-designed 4D printing biodegradable material filler is implanted into the defective breast tissue, and breast reconstruction is successfully performed.

4D printing technology relies on the development and application of shape memory materials. Greningerh and Mooradian in 1938, usa, discovered shape memory alloys, and k. ullakko et al, 1996, achieved 0.2% recoverable strain in stoichiometric Ni-Mn-Ga single crystals and confirmed that the strain was caused by the reorientation of martensitic twinned crystal modifications. Magnetic shape memory alloys represented by Ni-Mn-Ga have attracted considerable attention and interest from researchers. Dozens of Shape Memory alloys (SMA for short) with different Memory functions have been discovered so far, and have the advantages of excellent mechanical property, moderate cost, high strength, corrosion resistance, no toxicity and durability. Shape Memory Polymers (SMP), also known as Shape Memory polymers. The principle of the shape memory function of the thermotropic SMP was first discovered in Japan Shitian Zhengxiong. Compared with shape memory alloy, the shape memory plastic has the advantages of large deformation, easy processing, convenient shape response adjustment, good heat preservation and insulating property, etc., and is not rusted, easy to color, printable, light and cheap, thereby being widely applied. With the Cold Hibernating Elastic Memory (CHEM) process, SMP is widely used in the fields of flexible electronics, biomedicine, aerospace, etc. The shape memory plastic prepared in the current laboratory has good mechanical property and deformation capability (the deformation can reach 300-400 percent), excellent shape memory property and proper deformation temperature (in the range of about 60-75 ℃). In 2002, the Emerson electric investment Limited company in China invented a shape memory ceramic and a preparation method thereof. In 2008, hong Kong Richter university in China invented a ring-shaped shape memory polymer, and in the building structure, SMA is mainly applied to a damper for anti-seismic and shock absorption control. In 2002-2010, Qinghua university li qing bin project group eccentrically implanting SMA into a concrete member to form a prestressed alloy concrete beam type structure. A method for intelligently repairing a concrete structure by adopting SMA (shape memory alloy) is adopted by Wangwei of university of Coptis 2010 and the like. In 2013, the picrorhiza kurroa and the like invent a high polymer material with a water response shape memory function. In 2014, a novel 160 ℃ activatable FeMnSi shape memory alloy is researched by Switzerland and is considered to be applicable to the field of building industry. In 2015, chenqing invented a shape memory alloy material for three-dimensional printing and a preparation method thereof, and in 2016, Wang Chun and the like proposed a pressure sensitive shape memory material and a preparation method thereof. In 2016, 1 month, the subject group of professor of chemical engineering and bioengineering colleges of Zhejiang university develops novel shape memory plastic, can be 'implanted' into complex shape memory for multiple times, and shows various deformations when heated. In 2016, the university of Rochester, USA developed a new type of temperature sensitive shape memory polymer, which released energy by deformation 1000 times its weight. In 2017, a super-light shape memory alloy is developed at northeast university of Japan, can bear dozens of times of strain of common metal at a specific temperature, and shows super-elasticity.

The shape memory material is combined with the 3D construction technology to form the 4D intelligent construction technology which is constructed automatically in the whole process, and the method is suitable for construction of building structures in areas with severe environments, such as post-disaster reconstruction environments, polar environments, submarine environments or rapid space structure construction in space environments.

Disclosure of Invention

The invention aims to provide an intelligent construction method of a 4D printing folding space structure, which adopts a shape memory material with large deformation and good controllability as a control node and a high-strength material as a building frame to provide structural frame support, a light film material provides structural external closure, a time-varying signal is set to control deformation to create a space model, so that the 4D printing folding space building structure is formed, and the method can be unfolded and folded, and is automatic in the whole construction process.

The invention provides the following technical scheme:

A4D printing folding space structure intelligent construction method comprises the following steps:

(1) determining a high-strength building material and a shape memory material according to the structural functional requirement and the service standard, determining the spatial structure shape in the normal use state, and performing spatial optimization and mechanical analysis on the structural frame;

(2) determining a use working condition according to functional requirements, designing different structural folding states, and determining the shape, the number and the rotation deformation parameters of the spatial positioning key nodes according to the different structural folding states;

(3) determining the space node shape and the mass distribution of the shape memory material according to the stress of the space frame structure and the requirement of the folding process, and determining the geometric models of the high-strength steel fixing member and the rotating member;

(4) manufacturing a space frame by using a high-strength building material additive according to a digital design model by adopting 3D printing, manufacturing a node by using a shape memory material additive, and manufacturing the node and a light film material according to an initial state in a combined manner;

(5) and controlling the deformation in steps according to different folding design states of the structure, thereby realizing self-adaptive intelligent construction.

Preferably, the shape memory material forming the novel space structure comprises shape memory materials with shape memory performance, such as shape memory alloy, shape memory polymer, shape memory ceramic, shape memory polymer material and the like; the building materials forming the novel space structure comprise various materials with high strength, such as metal, fiber composite materials, high polymer materials and the like, which can be manufactured in an additive mode; the film material forming the novel space structure comprises various light, high-strength, heat-insulating, light, thin and foldable composite materials, such as one or more of glass fiber and Polytetrafluoroethylene (PTFE) dispersion resin films, polyester surface layer PVC film materials, polyester films (ETFE) and the like.

Preferably, in the step (5), the excitation information is programmed according to different folding design states of the structure, and the step-by-step deformation is controlled by an electric signal, so that the self-adaptive intelligent construction is realized. Specifically, the automatic building and controllable folding functions are realized by programming the excitation signal of the preset time-varying shape memory material.

Preferably, in the step (5), the node shapes and quality light sensation are designed according to different folding design states of the structure to deform in steps, so that the structure is automatically opened in a natural light state and automatically folded in a non-light state, and self-adaptive intelligent construction is realized. The structural design can be used for the intelligent construction of the space base structure.

According to the intelligent construction method of the 4D printing folding spatial structure, provided by the invention, in the building engineering, the shape memory material is used as a time-varying folding deformation control, the high-strength building material is used as a bearing framework, the light film material is used as an external enclosure, and the time-varying folding combination is controlled by information such as light, electricity and heat to form the spatial structure. Specifically, the method comprises the following steps: according to a digital design model, a structural framework is formed by high-strength building materials in an additive manufacturing mode, a steering control node is formed by shape memory materials, meanwhile, the shape memory material control node is controlled by setting optical/electric/thermal time-varying signals to cooperate with a numerical control folding external sealing film and the high-strength building material framework to complete folding, rotating and deforming so as to realize time-varying spatial modeling, and the method for printing the folding intelligent building structure is realized.

The 4D printing folding structure space intelligent building method provided by the invention is different from the structure building depending on the traditional manufacturing technology, the structural members and the node connection thereof consider different folding states of the space structure, and the digital design and the additive manufacturing are adopted; compared with the manual integrated construction of the traditional structure construction, the method is not assisted by excessive construction machinery and manual assistance, and only needs a computer to respectively perform calculation analysis and control parameter optimization aiming at an initial state, an intermediate state and a development state, so that the integral structure is digitally manufactured by control signals, and the automatic construction is realized.

The structure space design of the 4D printing folding structure space intelligent construction method provided by the invention is not limited to the traditional structure plane design, the facade design and the structure static/dynamic design, and also comprises the space structure stress design and the body type optimization of multiple folding states and multiple working conditions.

Due to the adoption of the technical scheme, the invention has the following beneficial effects:

1. the automatically built 4D printing space folding structure is suitable for building structure construction in areas with severe environments, such as post-disaster repair or reconstruction of environments, polar environments, submarine environments or rapid space structure construction in space environments.

2. The automatically built 4D printing space folding structure can combine the advantages of current material science, signal control, space structure modeling design and structural mechanics analysis of various subjects to form a novel intelligent building technology, more saves manufacturing/transportation space, builds a building structure with higher efficiency, greatly reduces energy consumption and saves carbon emission.

3. The automatically built 4D printing space folding structure adopts the multi-folding-state space modeling optimization design, and maximizes the mechanical property and the deformation property of the used material.

Drawings

FIG. 1 is a schematic diagram of a structural variation of a shape memory material;

FIG. 2 is a flow chart of 4D printing folding structure space structure digital design and intelligent construction;

FIG. 3 shows the structure and the configuration of each stage of a 4D printed and folded single-layer industrial factory building in example 1;

FIG. 4 is a folding structure component of a single-story industrial plant according to example 1;

FIG. 5 shows the folding structure and the various stages of the 4D printing folding cylinder;

FIG. 6 shows the folding structure of the light cylinder in example 2.

Detailed Description

The invention is further illustrated by the following examples in conjunction with the accompanying drawings:

the 4D printing folding structure space structure digital design and intelligent construction flow chart provided by the invention is shown in figure 2.

Example 1

The 4D construction technology is demonstrated by a single-layer industrial factory building frame structure:

1. determining that the high-strength building material is a high-strength steel material according to the structural function requirement and the service standard, determining that the shape memory material is a nickel-titanium alloy, and optimizing the space structure into a single-layer frame structure frame according to the use working condition and the load combination state;

2. structural mechanics analysis is carried out by combining the requirement of the bearing capacity extreme state, according to different structural folding states, as shown in figure 3, a is a printing completion initial state, b is an intermediate state 1, c is an intermediate state 2, d is an unfolding state, the shape, the number and the rotation deformation parameters of the space folding key nodes are determined, and command stream programming is realized;

3. determining the shape and the mass distribution of the nickel-titanium alloy memory material space nodes according to the requirements of the space frame structure in the stress and folding process, and determining a geometric model of a high-strength steel fixing component and a rotating component, wherein the geometric model is shown in figure 4, wherein 1 is a nickel-titanium alloy node, 2 is a high-strength steel component, and 3 is a rotatable high-strength steel component;

4. manufacturing a space frame by using a high-strength steel material additive according to a digital design model by adopting 3D printing, manufacturing nodes by using a nickel-titanium alloy shape memory material additive, and manufacturing and combining the nodes and a light film material according to an initial state;

5. and programming excitation information according to different folding design states of the structure, and controlling the step-by-step deformation by using an electric signal to realize self-adaptive intelligent construction.

Example 2

The 4D construction technique is demonstrated with a folded cylinder structure as an example:

1. determining that the high-strength building material is an FRP composite material according to structural function requirements and service standards, determining that the shape memory material is light induced group polyurethane, and optimizing a spatial structure cylinder structure according to the use working condition and the load combination state;

2. structural mechanics analysis is carried out by combining the requirement of the bearing capacity extreme state, according to different structural folding states, as shown in figure 5, a is a printing completion initial state, b is an intermediate state 1, c is an intermediate state 2, d is an unfolding state, the shape, the number and the rotation deformation parameters of the space folding key nodes are determined, and command stream programming is realized;

3. determining the shape and the mass distribution of the nickel-titanium alloy memory material space nodes according to the stress of the space frame structure and the requirements of the folding process, and determining a geometric model of a high-strength steel fixing component and a rotating component, as shown in figure 6, wherein 4 is a light-induced base polyurethane-aggregated node, and 5 is a high-strength FRP component;

4. manufacturing a space frame by using a high-strength steel material additive according to a digital design model by adopting 3D printing, manufacturing nodes by using a photoinduced radical polyurethane shape memory material additive, and manufacturing and combining the nodes and a light-weight high polymer film material according to an initial state;

5. the node shapes and quality light sensation deformation are designed according to different folding design states of the structure in steps, the structure is automatically opened in a natural light state, the structure is automatically folded in a non-light state, self-adaptive intelligent construction is achieved, and the structural design can be used for intelligent construction of the space base structure.