IMPACT ENERGY ABSORBER STRUCTURE IMPROVED BY MONOLITHIC INTEGRATION OF OXETIC AND LATTICE GEOMETRIES AND ITS MANUFACTURING METHOD

Abstract

The invention relates to an impact energy absorber structure developed through the monolithic integration of auxetic and lattice geometries. Specifically, the invention concerns a hybrid structure formed by integrating a three-dimensional lattice structure with an auxetic geometry having a negative Poisson ratio.

Description

1 TARIFF MONOLITHIC INTEGRATION OF OXETIC AND LATTICE GEOMETRIES IMPROVED SURGE ENERGY ABSORBING STRUCTURE AND ITS PRODUCTION. METHOD Technical Area 5 The invention is an impact engineered through the monolithic integration of orchethic and lattice geometries. It is related to its energy-absorbing structure. The invention specifically relates to three-dimensional lattices with austereic geometry that has a negative Poisson ratio. It relates to a hybrid structure created through the integration of the building. State of the Art 10 The effective absorption of impact and collision energy is of paramount importance. in the automotive, defense industry, aviation and personal protective equipment sectors the structural elements used exhibit a high energy absorption capacity on the one hand, On the other hand, having a minimum weight characteristic is a fundamental requirement. This is what we encounter. The kinetic energy generated during a collision or impact can be controlled in a controlled manner. 15 absorption in this manner and preservation of structural integrity, ensuring life safety and equipment safety. Reliability is considered an important performance criterion. In the current state of the art, energy-absorbing structures are generally made of conventional materials and They are manufactured using production methods. Among these structures is the honeycomb. (honeycomb) structures, foam-based materials, corrugated metallic tubes, and various sandwich 20 Panel configurations are widely used. However, these structures... The majority are based on uniform and homogeneous geometric arrangements, and this situation Significantly effective in distributing and absorbing impact energy within the structure. It creates limitations. Especially in one-sided coup scenarios, it is not satisfactory. These structures, which demonstrate high performance, can operate under multi-axial or complex loading conditions up to 25. This may be insufficient. This limitation stems from the geometric nature of energy absorption mechanisms. This stems from a lack of diversity and adaptive structural behavior. One of the most significant problems with current energy absorption systems is their weight and mechanical properties. The difficulty lies in striking a balance between durability and quality. Traditional designs are insufficient. To achieve the energy absorption capacity, the material thickness is usually 30% or more. 2 This requires increasing the density, which inevitably leads to increased structural weight. This leads to an increase in specific energy absorption values ​​and a decrease in specific energy absorption values, especially. In the aerospace and automotive industries, weight minimization is a crucial design parameter. Therefore, this situation represents a significant loss of productivity. However, Weight reduction efforts often come at the expense of mechanical strength and energy absorption. 5 This requires compromising capacity, and therefore safety standards. This poses a risk in ensuring its availability. When evaluated in terms of production processes, current technologies have significantly improved. It involves complexity and cost disadvantages. Traditional manufacturing methods... Molding, casting, welding and mechanical joining processes for complex geometries 10 The production of monolithic structures is time-consuming and costly, especially three-dimensional ones. In designs requiring lattice structures or nested geometric arrangements, multiple The production of parts and their subsequent assembly becomes necessary. This situation in production... This prolongs the process and brings with it the risk of assembly-related errors. Furthermore... The connection points create structural weakness areas, affecting the overall mechanical performance by 15. It can have negative effects. Another significant shortcoming in the current state of the art is the limitations of existing energy-absorbing structures. Limited ability to adapt to different impact scenarios and loading conditions. The reason is that structures with a fixed geometric configuration can withstand a specific impact velocity, angle, or It was developed for energy levels, but performance losses occur under varying conditions. This is happening. This situation can be encountered, especially in real-world usage conditions. In unpredictable coup scenarios, security margins are exceeded and structural damage occurs. This can lead to an increase. Additionally, material homogeneity and uniform cell type are important. Designs based on this geometry lead to limited energy absorption mechanisms. It opens. 25 In the current state of the art, lightweight and high energy absorption are required for energy-absorbing structures. capacity, ease of production and versatile performance criteria simultaneously This remains a significant technical problem that needs to be addressed. In conclusion, due to the negative aspects described above and the current solutions being the subject of discussion... Due to its shortcomings, an improvement in the relevant technical field is necessary. 30 It has been made. 3 Purpose of the Invention The invention was created by drawing inspiration from existing situations and overcoming the aforementioned drawbacks. It aims to solve the problem. The main objective of the invention is to overcome the energy absorption deficiencies encountered in the known state of the art. 5 issues such as weight-strength imbalance, complex production processes, and high cost. The aim is to present an energy-dissipating structure that will eliminate the problems. In this context, the invention, Integration of three-dimensional lattice structure with auxetic geometry having a negative Poisson ratio. It presents a hybrid structure created through a process involving chopped carbon fiber. Monolithic production by additive manufacturing using reinforced polylactic acid (PLA) filament. It is produced in this way and thus has the production and 10 of traditional energy absorber systems. It presents a technical solution that overcomes performance limitations. Another objective of the invention is to effectively dampen impact and collision energy. The goal is to develop a deformation mechanism that will provide this. To this end, Re-entrant type oxetic cells located on the outer perimeter of the structure, impact loading Unlike traditional structures, instead of expanding outwards, it expands inwards. It exhibits shrinkage behavior, thereby enabling a high degree of energy absorption. This is being carried out. The negative Poisson ratio property of mistletoetic cells causes an impact on the structure. It provides a unique deformation capability underneath and an energy absorption mechanism. It significantly increases its efficiency. This geometric feature, existing uniform and homogeneous It provides a versatile energy distribution capacity not seen in buildings. 20 Another objective of the invention is a parametric grid positioned within the interior of the structure. The aim is to further increase the energy absorption capacity through its geometry. The internal lattice structure, They have optimized cell geometries and carry loads by filling the voids. It enhances its capabilities and maximizes its energy absorption performance. The fact that the lattice geometry can be designed parametrically, including cell type, cell size, 25 variables such as occupancy rate and wall thickness depending on the application requirement It allows for customization, thus enabling adaptation to different coup scenarios. This capability is provided by the synergistic combination of these two different geometric structures. thanks to a multi-stage design that absorbs impact energy at different levels. A deformation mechanism is created, and compared to classical energy-dissipating structures, it is 30 Greater energy absorption is achieved, and the specific energy absorption values ​​of the structure are significant. is being increased to a certain extent. 4 Another aim of the invention is to simplify production processes and minimize costs. The complex assembly processes encountered in traditional production methods are very... The entire process of component production and mechanical assembly is called additive manufacturing. This is eliminated by the use of technology. The production process is completely additive-free. It is carried out without assembly and without installation, and computer-aided design 5 The holistic three-dimensional model created in the environment utilizes fused deposition modeling technology. It is manufactured directly using the additive manufacturing method on a three-dimensional printer. This monolithic production approach, resulting from welding or mechanical joining points. It completely eliminates structural weaknesses and significantly shortens production time. and provides cost effectiveness in the prototyping and mass production phases. 10 Another aim of the invention is to strike a balance between high mechanical performance and lightness. The goal is to establish a material made of chopped carbon fiber reinforced polylactic acid, chopped carbon. a composite obtained by homogeneously distributing fibers into a polylactic acid matrix It is a thermoplastic and has a much higher modulus of elasticity compared to traditional polylactic acid. It offers enhanced impact resistance and increased heat resistance properties. This 15 Through the selection of materials, the mechanical strength of structures is increased while the weight is significantly reduced. is being reduced, and thus in sectors such as the automotive, aerospace and defense industries. The expected performance criteria are being met. Another aim of the invention is to provide design flexibility and customization capabilities. Cage Parameters such as density, cell type, and cross-support can be adjusted via software. The fact that it can be modified allows the product to be improved according to its application area, and in different sectors such as automotive, aerospace, defense or personal protective equipment Customized solutions can be offered. This feature allows for the development of existing fixed-geometry structures. directly reflects its inability to adapt to different coup scenarios. It eliminates. 25 To achieve the purposes described above, the invention utilizes impact and collision energy. It is a hybrid energy absorber structure with a monolithic structure designed to provide damping,  three-dimensional, positioned within the interior of the hybrid energy absorber structure as a cross-lattice system consisting of repeating unit cells structured; ensuring effective distribution of impact loads within the structure 30 and to enable its localization, micro-level energy absorption. a geometric shape that enables deformation in multiple directions It has an arrangement; the unit cells within it are in three-dimensional space. a network system that improves directional robustness through systematic repetition created by controlled collapse mechanisms during deformation it allows for activation and gradual and continuous energy absorption. Having a porous structure that prevents it from happening in any way; Cage 5 to ensure the absorption of the initial deformation upon impact. structure and  Forming the outer perimeter of the hybrid energy absorber structure and functioning as the primary force carrier. The macro-scale structural component that is seen is a regularly arranged inverted structure. composed of cells with prismatic geometry; having a negative Poisson ratio. its behavior of shrinking inwards under impact loading 10 exhibiting the deformation of the cage structure located in the interior. acting as a guiding framework; a controlled structure of the lattice system. enabling the collapse to occur simultaneously and in coordination with the lattice structure. Oxetic structure that operates through deformation It contains. 15 To achieve the purposes described above, the invention is a hybrid energy absorber. It is a production method for,  Holistic analysis of lattice structure and orthogonal structure in a computer-aided design environment modeling as such,  Exporting the created three-dimensional model in stereolithography format, 20  The exported model has a three-way interface with fused stacking modeling technology. monolithic production using the additive manufacturing method on a 3D printer. It includes the steps involved in the process. The structural and characteristic features and all the advantages of the invention are given in the figures below. Thanks to the detailed explanation written with references to these figures, 25 is more clearly understood. This will be understood, and therefore the evaluation should also take these forms and detailed explanations into consideration. It needs to be done by taking precautions. Figures that will help understand the invention. Figure 1 shows the isometric view of the lattice structure. Figure 2 is an isometric view of the oxetic structure. 30 Figure 3 is an isometric view of the hybrid energy absorber structure that is the subject of this invention. 6 Explanation of Part References 1. Lattice structure 2 Oxetic structure A hybrid energy absorber structure Detailed Description of the Invention 5 In this detailed description, the preferred hybrid energy absorber structure (A) which is the subject of the invention is described. Their structures are explained solely to facilitate a better understanding of the subject. The invention is designed for the efficient absorption of impact and collision energy. This relates to the hybrid energy absorber structure (A), which has been developed and has a multi-scale structure. The subject is a hybrid energy absorber structure (A), essentially a synergistic combination of two different geometric systems. It is based on integration and these systems are called lattice structure (1) and oxetic structure (2). They are called. Both structural components are chopped carbon fiber reinforced polylactic acid. It is produced as a single piece using additive manufacturing with filament, and thus A monolithic energy dissipation system is obtained. The lattice structure (1) is located in the interior region of the hybrid energy absorber structure (A) and consists of three 15 as a cross-lattice system composed of dimensionally repeating unit cells It has been designed. The lattice structure (1) performs energy absorption at the micro level and It has a geometric arrangement that allows for deformation in multiple directions. This The main characteristic of the structure is its high impact resistance despite being porous and lightweight. It is able to present. Unit cells within the lattice structure (1) systematically in three-dimensional space 20 It creates a network system that improves directional robustness by repeating this pattern. The geometric configuration of the unit cells ensures that impact loads are effectively distributed within the structure. This ensures that energy is distributed and localized in this way, thus facilitating energy absorption. Its performance is significantly improved. The lattice structure (1) offers a high surface area. Because of this, it can distribute the impact energy over a large volume, thus providing structural protection. It is able to maximize energy absorption capacity while minimizing damage. (Cage) (1) porous structure of the structure, controlled collapse mechanisms during deformation This allows for the activation of the system, and this results in gradual and continuous energy absorption. It ensures that it happens in some way. The oxetic structure (2) forms the outer wall of the hybrid energy absorber structure (A) and the basic force is 30 It is a macro-scale structural component that functions as a carrier. The oxetic structure (2) is arranged in an orderly manner. 7 It consists of cells with an inverted prismatic geometry placed in a structure, and these cells Each has a specific geometric configuration, referred to as a re-entrant type. The most distinctive feature of the oxetic structure (2) is that it has a negative Poisson ratio and this This allows it to move outwards under impact load, unlike traditional materials. It exhibits a behavior of contracting inwards instead of expanding. This deformation is 5. This characteristic significantly increases the efficiency of the energy absorption mechanism. The orchetic structure (2) deforms the lattice structure (1) located in the inner region. It acts as a guiding framework and provides directional stiffness (A) to the hybrid energy absorber structure. It provides. The oxetic structure (2), which functions as the outer layer, takes shape under load. to ensure stability and to allow the cage structure (1) to collapse in a controlled manner 10 This helps in this way. In this way, the impact energy is systematically distributed within the structure. It is being distributed and undergoing a gradual and controlled deformation process instead of a sudden collapse. It takes place. The macro-scale cells of the oxetic structure (2) transfer the load. by improving the controlled transmission of the impact forces to the cage structure (1) This ensures structural integrity is preserved. 15 The hybrid energy absorber structure (A) is formed as a result of the combination of the lattice structure (1) and the oxetic structure (2). and multi-scale integration of micro-cages placed inside outer macro-cells It is designed as a system. In this hybrid structure, the micro-scale lattice structure (1) is high While offering surface area and energy absorption capacity, the macro-scale oxetic structure (2) load It directs the transfer and controls the collapse mode. Hybrid energy absorber 20 The working principle of structure (A) is that the first deformation during impact occurs in the inner region. to be absorbed by the positioned lattice structure (1), then in the outer region the oxetic structure (2) directs the energy and the final deformation geometry It is based on the definition of this multi-stage deformation mechanism, impact. 25 and thus the total energy absorption capacity is maximized. The lattice structure (1) micro-scale cells absorb energy by localizing impact loads, while the oxetic structure (2) It directs deformation and preserves structural integrity. This synergistic interaction... Thanks to this, the hybrid energy absorber structure (A) offers high specific energy absorption values ​​and It is able to keep the structural weight to a minimum. 30 The hybrid energy absorber structure (A) was manufactured using entirely additive manufacturing technology. The production process is carried out using a lattice structure in a computer-aided design environment (1). and begins with the holistic modeling of the oxetic structure (2). The three created The three-dimensional model is exported in stereolithography format and then subjected to fusion deposition modeling. 8 It is manufactured using the additive manufacturing method on a 3D printer with advanced technology. The material used in production is chopped carbon fiber reinforced polylactic acid filament, This material consists of chopped carbon fibers homogeneously embedded in a polylactic acid matrix. It is a composite thermoplastic obtained by dispersing chopped carbon fiber reinforced material. Polylactic acid material has approximately seven gigapascals 5 compared to traditional polylactic acid. with a high level of elasticity modulus, increased impact resistance and improved heat dissipation. It has durability characteristics. Production parameters of the hybrid energy absorber structure (A) It is being improved according to its geometric properties, and the layer height is 0.2 millimeters. It is being adjusted, the fill rate is selected between 20-50%, and the nozzle diameter is cage-like. Depending on its density, it is varied between 0.4 millimeters and 0.6 millimeters. This 10 Thanks to the monolithic production approach, the lattice structure (1) and the oxetic structure (2) are in one piece. and without the need for any assembly, welding or mechanical joining process It is produced. Design of hybrid energy absorber structure (A), adjustment according to application requirements. It allows for the construction of the cage structure (1) cell type, cell size, occupancy 15 Geometric parameters such as ratio and wall thickness are determined by computer-aided design software. It can be modified accordingly, thus making it suitable for different coup scenarios. configurations can be created. Similarly, the re-entrant of the oxetic structure (2) Cell angles, wall thickness, and cell dimensions can also be adjusted parametrically. This design flexibility makes the hybrid energy absorber structure (A) suitable for the automotive, aerospace, and defense industries. and being able to offer customized solutions in different sectors such as personal protective equipment It provides this. Especially in applications requiring high impact resistance, the cage Maximum energy absorption thanks to the synergistic interaction of the structure (1) and the oxetic structure (2). This is ensured, and structural weight is kept to a minimum. The working mechanism of the hybrid energy absorber structure (A) is cage 25 under impact loading. simultaneous and coordinated deformation of the structure (1) and the oxetic structure (2) It is based on. At the moment of impact, the microcells of the cage structure (1) are first plastic. It begins to deform and absorbs energy by localizing it. This In the stage, the cross elements of the lattice structure (1) bending and axial compression It performs energy absorption through this combination. Simultaneously, 30 The negative Poisson ratio property (2) of the oxetic structure comes into play and the structure moves inwards By exhibiting contraction behavior, it distributes the impact forces over a wider area. This dual mechanism enables the absorption of impact energy at both micro and macro scales, and thus achieving much higher performance compared to traditional single-scale energy absorber structures. 9 is obtained. During the deformation process, the oxetic structure (2) collapses into the lattice structure (1). controlling the mode and ensuring a gradual crash instead of a sudden crash. As a result, the hybrid energy absorber structure (A) provides maximum energy absorption. It is able to maintain its structural integrity even after the coup.

Claims

REQUESTS 1. A monolithic structure to provide absorption of impact and collision energy. The hybrid energy absorber structure (A) has the following features:  three located in the inner region of the hybrid energy absorber structure (A) a cross-lattice system consisting of dimensionally repeating unit cells 5 It is structured in such a way that impact loads are effectively distributed within the structure. micro-level energy to enable its distribution and localization. It enables absorption and allows deformation in multiple directions. It has a geometric arrangement; the unit cells within it are three-dimensional. A network that improves directional stability by systematically repeating itself in space. 10 the system creates; controlled collapse during deformation enabling the activation of mechanisms and energy absorption porous in order to prevent it from happening gradually and continuously having a structure that absorbs the initial deformation upon impact. cage structure (1) and 15 to provide  The outer wall of the hybrid energy absorber structure (A) and the main force carrier a macro-scale structural component that performs a function; in a regular manner consisting of cells with an inverted prismatic geometry arranged in a negative manner; Due to its Poisson ratio, it moves inwards under impact loading. exhibiting shrinkage behavior; cage 20 located in the interior a frame which acts as a guide for the deformation of the structure (1); lattice cage that enables the structure (1) to collapse in a controlled manner. The oxetic structure working through simultaneous and coordinated deformation with structure (1) (2) It includes. 25 2. A manufacturing method for a hybrid energy absorber structure (A) conforming to Claim 1, and its characteristic is;  Lattice structure (1) and oxetic structure (2) in computer-aided design environment holistic modeling,  Exporting the created three-dimensional model in stereolithography format,  The exported model has a three-part system with fused stacking modeling technology. monolithic production using the additive manufacturing method on a 3D printer. 11 It includes the steps of the process.

3. A method that complies with Claim 2, characterized by its use in production with chopped carbon fiber reinforcement. It involves using polylactic acid filament as the material.

4. A method conforming to Claim 3, characterized by its use of chopped carbon fiber reinforced polylactic acid. the material, chopped carbon fibers homogeneously embedded in a polylactic acid matrix 5 It is a composite thermoplastic obtained by dispersing it in a certain way.

5. A method that conforms to any of the previous requirements and has the characteristic of being a layer. its height is chosen as 0.2 millimeters.

6. A method suitable for any of the previous requests, characterized by its occupancy rate. It is chosen between 20-50%. 10 7. A method that meets any of the previous requirements, characterized by its nozzle diameter. between 0.4 millimeters and 0.6 millimeters depending on the lattice density. It is a change.

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