Three-dimensional printing strain meter applied to a three-dimensional

Abstract

A strain gauge applied to a component used in a crash test dummy is used to assess performance of the component during a crash test simulation. The strain gauge may be applied directly to the outer surface of the component using three-dimensional printing, or may be applied to a polymeric sheet having an adhesive backing that is subsequently applied to the outer surface of the component. The strain gauge may then be electrically coupled through the wire harness to a controller to measure a change in an electrical signal of the strain gauge, the change corresponding to a change in strain of the rib occurring within a time span of 10 to 200 milliseconds during the impact test simulation.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to and all the benefits of U.S. Provisional Patent Application No. 63 / 490,710 (filed on March 16, 2023), the entire contents of which are hereby incorporated by reference herein. Technical Field

[0002] The present invention relates generally to crash test dummies and, more particularly, to three-dimensionally printed strain gauges and methods of three-dimensionally printing strain gauges directly or indirectly onto three-dimensional printed parts for crash test dummies. Background Art

[0003] Automobile, aircraft, and other vehicle manufacturers conduct a variety of crash tests to evaluate the effects of collisions on vehicles and their occupants. Crash tests provide vehicle manufacturers with valuable data that can be used to improve vehicle design, regulators use this data to review vehicles for type certification, and consumer organizations provide the public with information on vehicle safety ratings.

[0004] Crash testing typically involves using humanoid test devices, known as "crash test dummies," to assess human injury risk. These dummies must possess the overall mechanical characteristics, dimensions, mass, joint structure, and joint stiffness of the target population. Furthermore, they must exhibit sufficiently similar mechanical shock response and sensitivity to allow them to interact with the vehicle's interior in a human-like manner. These crash impacts typically occur over short timescales (e.g., between 10 and 200 milliseconds) and exert significant forces, such as over 3,500 or 7,000 Newtons, on specific parts of the crash dummy.

[0005] The present invention relates to coupling evaluation tools to components of a crash test dummy to enable improved evaluation of those components during and after a crash test simulation. Summary of the Invention

[0006] The present invention provides a three-dimensional printed strain gauge for use on a three-dimensional printed component of a crash test dummy, and an associated method for applying the three-dimensional printed strain gauge directly or indirectly to the three-dimensional printed component of the crash test dummy to define an integrated sensor on the three-dimensional printed component, wherein when the three-dimensional printed component is subjected to a sudden impact, the integrated sensor will cause strain within a very short time span (i.e., the time of the impact simulation, for example, within a time span of 10 to 200 milliseconds).

[0007] In certain embodiments, the three-dimensional printed part is a three-dimensional printed rib, such as a three-dimensional printed rib included as part of a thorax assembly of a crash test dummy.

[0008] In some embodiments, the 3D printed strain gauges are printed directly onto the outer surface of a 3D printed part (eg, a 3D printed rib).

[0009] In certain other embodiments, a 3D-printed strain gauge is printed on a first side of a polymer sheet, which is then coupled to an outer surface of a 3D-printed component such that the polymer sheet is positioned between the 3D-printed component and the 3D-printed strain gauge. In some of these embodiments, an adhesive backing is applied to an opposing second side of the polymer sheet, wherein an adhesive of the adhesive backing is used to bond the polymer sheet to the outer surface of the 3D-printed component.

[0010] The 3D printed strain gauge can then be electrically coupled to a control unit via wires from a wiring harness, which are electrically coupled to the ends of the strain gauge via welded joints. Once electrically coupled, the 3D printed part can be used to perform single or repeated crash test simulations on a crash test dummy, where the 3D printed part is shaped and sized to simulate how a corresponding part of the human body would behave under the same crash test conditions.

[0011] Other features and advantages of the present disclosure will become apparent as understanding deepens from reading the following description in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a perspective view of one embodiment of a thorax assembly prior to incorporation of 3D printed strain gauges thereon, illustrating its operational relationship with a crash test dummy.

[0013] Figure 2 is a side view of the thoracic component, showing its Figure 1 The operational relationship between the crash test dummies.

[0014] Figure 3 Before the introduction of one or more 3D printed strain gauges Figure 1 and Figure 2 A top view of one embodiment of a 3D printed rib for a thoracic cage assembly.

[0015] Figure 4 yes Figure 3 Side view of the 3D printed ribs.

[0016] Figure 5 Is used for printing Figure 3-Figure 4 A schematic diagram of one embodiment of a 3D printing system for 3D printing ribs.

[0017] Figure 6 According to the present disclosure, Figure 3-Figure 4 Flowchart of a method for 3D printing of 3D printed ribs.

[0018] Figure 7 is a device for use in accordance with an alternative embodiment including a pair of three-dimensional printed strain gauges formed thereon. Figure 1 A perspective view of the 3D-printed ribs in a crash test dummy.

[0019] Figure 8 is used in accordance with an alternative embodiment prior to the introduction of one or more three-dimensional printed strain gauges Figure 1 A perspective view of the 3D-printed half-rib in a crash test dummy.

[0020] Figure 9 This is after the introduction of multiple 3D printed strain gauges formed on it Figure 8 A perspective view of the 3D-printed half rib.

[0021] Figure 10 includes a plurality of three-dimensional printed strain gauges formed thereon Figure 8 A perspective view of an alternative embodiment of a 3D printed rib.

[0022] Figure 11 is another perspective view of a 3D printed half-rib having a pair of 3D printed strain gauges formed therein, wherein one of the 3D printed strain gauges is electrically connected to a controller via a wiring harness.

[0023] Figure 12 is another perspective view of a 3D printed full rib with 3D printed strain gauges printed on a polymer film coupled to the outer surface of the rib and the strain gauges electrically connected to a controller via wiring harnesses.

[0024] Figure 13 is a flow chart of a method according to the present disclosure, the method being based on Figure 6 The method is constructed to further include the step of coupling a wiring harness and an electrical component of a controller to the strain gauge.

[0025] Figure 14 is a flow chart of a method according to the present disclosure for evaluating a vehicle in one or more crash test simulations. Figure 13 The modified reinforcing ribs formed. DETAILED DESCRIPTION

[0026] The present application relates to incorporating a 3D-printed strain gauge (Note: the term "strain gauge" in "gauge" can also be spelled "gage," and is therefore equivalent to the term "strain gage," and are used interchangeably herein) into one or more 3D-printed components of a crash test dummy. For ease of description and in accordance with the exemplary embodiments provided below, the 3D-printed strain gauge is described with respect to its use on one or more 3D-printed ribs of a crash test dummy's thorax assembly. However, it is contemplated that the 3D-printed strain gauge described below could alternatively be used on any other 3D-printed component of a crash test dummy in the same manner as it is used on one of the 3D-printed ribs of the crash test dummy's thorax assembly.

[0027] With reference to the accompanying drawings and in particular with reference to Figure 1 and Figure 2 , one embodiment of a crash test dummy is generally indicated at 12. The crash test dummy 12 is of the fifth percentile (5%) female body type and is shown in a seated position. The crash test dummy 12 is primarily used to evaluate the performance of a vehicle's interior and restraint systems for adult occupants in the front and rear seats. The dimensions and weight of the crash test dummy 12 are based on anthropometric studies, which are typically conducted independently by the following institutions: the University of Michigan Transportation Research Institute (UMTRI), the U.S. Military Anthropometric Survey (ANSUR), and the U.S.-European Civilian Surface Anthropometric Resource Center (CESAR). It should be noted that the range of motion, center of gravity location, and limb segment mass all simulate those parameters of a human subject defined by anthropometric data.

[0028] like Figure 1 and Figure 2 As shown, the crash test dummy 12 includes a head assembly 14 comprising a single-piece plastic skull, an instrument core, and a vinyl skin. The instrument core is removable to allow access to the head instruments housed within the head assembly 14.

[0029] The crash test dummy 12 also includes a spine assembly 15 having an upper end mounted to the head assembly 14 via a nod block (not shown) and a nod joint (not shown). The spine assembly 15 has a lower end extending into the torso region of the crash test dummy 12 and connected to a spine mounting weldment (not shown) via an adapter assembly (not shown).

[0030] The crash test dummy 12 includes a torso or thoracic assembly 16 connected to a spine assembly 15. The spine assembly 15 also includes a neck (not shown) connected to the head assembly 14 and a spine box (not shown) connected to the neck. The neck has a lower end connected to the spine box by a suitable attachment member (not shown), such as one or more fasteners. It should be noted that the fasteners threadably engage apertures (not shown) in the spine box to secure the neck to the spine box. The crash test dummy 12 also has a pair of arm assemblies, including a right arm assembly 18 and a left arm assembly 20, which are attached to the crash test dummy 12. The left arm assembly 20 includes a clavicle link (not shown) that connects the clavicle (not shown) to the top of the spine assembly 15. It should be noted that the right arm assembly 18 is constructed in an equivalent manner.

[0031] like Figure 1 and Figure 2 As shown, the lower end of the lumbar spine is connected to a lumbar-thoracic transition adapter (not shown), which is in turn connected to a lumbar-pelvic transition adapter (not shown). The crash test dummy 12 includes a pelvis assembly 22 connected to the adapter. The crash test dummy 12 also includes a right leg assembly 24 and a left leg assembly 26 attached to the pelvis assembly 22. It should be noted that various components of the crash test dummy 12 (such as the muscle and skin assemblies (not shown)) are covered with a polyurethane skin to enhance coupling with the crash test dummy 12 skeleton. It should also be noted that a lifting ring (not shown) can be attached to the head assembly 14 to facilitate lifting the crash test dummy 12 into and out of the test apparatus and vehicle.

[0032] Reference Figure 1 and Figure 2 The thoracic cage assembly 16 includes one or more ribs 36. The ribs 36 extend between the spinal box and the sternum 34. Figure 3 and Figure 4 As shown in one embodiment for the third rib, the ribs 36 are generally arcuate and rectangular, but may be of any suitable shape. The ribs 36 are vertically spaced apart along the spine box and the sternum 34. The ribs 36 are connected to the spine box and the sternum 34 by suitable means (e.g., fasteners (not shown)).

[0033] Each rib 36 is generally "C"-shaped and extends between a pair of opposite ends 37, 39 with a length AL (i.e., arc length AL). Figure 3 and Figure 7 and Figure 12 ), the rib 36 is a full rib 36A having the described "C" shape; while in other embodiments, the rib 36 is a half rib 36B (see Figures 8-11), which corresponds to the right rib 36B and the left rib 36B that are independently connected to the spinal box. Unless otherwise specifically stated, the description of the rib 36 specifically covers the description of the full rib 26A or the half rib 36B.

[0034] In the exemplary embodiment provided herein, each rib 36 preferably comprises at least two ribbon layers. In one embodiment, each rib 36 has a front ribbon layer 40 (i.e., first ribbon layer 40) and a rear ribbon layer 42 (i.e., second ribbon layer 42), which are separated by an inner portion 44. The front ribbon layer 40 and the rear ribbon layer 42 are made of ribbon material. The thickness of each layer 40 and 42 is about 2.0 mm to about 6.0 mm, preferably about 4.0 mm. Figure 3 As shown, each rib 36 preferably includes a layer of damping material 46 (i.e., damping layer 46) disposed between or sandwiched between the two strip layers 42 and 44; however, the damping layer 46 may be omitted in other embodiments (see Figures 8-11 When present, the damping layer 46 has a thickness of about 8.0 mm to about 10.0 mm, preferably about 9.5 mm. Each rib 36 includes at least one (and preferably a plurality) apertures 48 to allow fasteners (not shown) to extend therethrough to connect the thorax assembly 16 to the crash test dummy 12.

[0035] In certain embodiments, as Figure 3 As best shown, the rib 36 forms a first rectangular cross-section RCL1 comprising a damping layer 46 sandwiched between two ribbon-like layers 40, 42, the first rectangular cross-section extending along an axis A1 perpendicular to the first rectangular cross-section RCL1 to form an arcuate sub-length AL1 terminating at opposite ends 46A, 46B. Each of the opposite ends 46A, 46B forms a second rectangular cross-section RCL2 comprising a single ribbon-like layer 40, 42 devoid of the damping layer 46, the single ribbon-like layer extending away from the adjacent first rectangular cross-section damping layer 46 along the axis A1.

[0036] As will be described herein, in certain embodiments, ribs 36 are formed using a 3D printing process. The printable material for ribs 36 is available from Markforged, Inc. of Watertown, Massachusetts, under the trade name Markforged Onyx, a nylon material containing carbon fiber. It should be noted that the size and thickness of ribs 36 will vary depending on the crash test dummy. It should also be noted that the process is equally applicable to other rib designs, such as larger, smaller, or differently shaped ribs.

[0037] Reference Figure 5, a 3D printer or printing system (generally 110) includes one or more print heads 112 and at least two dispensers 114 (individually labeled 114A and 114B) that contain printable material (generally 116, respectively labeled 116A and 116B). It should be noted that other components or other sets of components may be used.

[0038] The printhead 112 has a plurality of inkjet nozzles 118 through which printable materials 116A and 116B are ejected. In one embodiment, a first dispenser 114A is connected to the first set of nozzles 118A, and a second dispenser 114B is connected to the second set of nozzles 118B. Thus, the first printable material 116A is ejected through nozzles 118A, and the second printable material 116B is ejected through nozzles 118B. In another embodiment (not shown), the 3D printing system 110 may include at least two printheads 112. The first printhead 112 is connected to the first dispenser 114A and is used to eject the first printable material 116A; while the second printhead 112 is connected to the second dispenser 114B and is used to eject the second printable material 116B.

[0039] The 3D printing system 110 further includes a controller 115, a computer-aided design (CAD) system 122, a curing unit 124, and an optional positioning device 126. The controller 115 is coupled to the CAD system 122, the curing unit 124, the positioning device 126, the print head 112, and each dispenser 114. It should be noted that control may also be implemented by other units other than those shown, such as one or more independent units.

[0040] One exemplary three-dimensional printing system 110 for forming ribs 36 according to the present invention is a Markforged printer available from Markforged, Inc. of Watertown, Massachusetts.

[0041] The three-dimensional printed ribs 36 are built up in layers, with the thickness of each layer generally being controllable by selectively adjusting the output from each inkjet nozzle 118 .

[0042] By combining or mixing the materials from each dispenser 114 (where each dispenser 114 contains printable materials having different hardnesses), the hardness of the material forming the three-dimensional printed rib 36 being produced can be adjusted and controlled. Thus, by combining the first and second interface materials outputted from each dispenser 114, different portions of the three-dimensional printed rib 36 having different elastic moduli and strengths can be produced. It should be noted that such a three-dimensional printing system is disclosed in U.S. Patent No. 8,481,241, issued to Napadensky et al., the entire contents of which are hereby expressly incorporated herein by reference.

[0043] Reference Figure 6 The present disclosure provides a method 200 for manufacturing a 3D printed rib 36 (as a full rib 36A or a half rib 36B) for a crash test dummy 12 according to one embodiment of the present disclosure. For ease of description, the formed rib 36 includes a damping layer 46, but the method can generally also form a 3D printed rib 36 without a damping layer 46.

[0044] The method 200 begins at bubble 202 and proceeds to block 204. At block 204, the method 200 includes providing a three-dimensional printer or printing system 110.

[0045] The method 200 proceeds to block 206 and includes the step of generating a CAD model of the rib 36. In one embodiment, the CAD model of the rib 36 is prepared to allow a three-dimensional printer to print the entire model in one go.

[0046] In certain embodiments, the method creates a first CAD model of the rib 36 that forms a first rectangular cross-section RCL1 comprising a damping layer 46 sandwiched between two ribbon-like layers 40, 42, the first rectangular cross-section extending along an axis A1 perpendicular to the first rectangular cross-section RCL1 to form an arc length AL1 terminating at opposite ends 46A, 46B. Each of the opposite ends 46A, 46B forms a second rectangular cross-section RCL2 comprising a single ribbon-like layer 40, 42 without the damping layer 46, the second rectangular cross-section extending along the axis A1 away from the adjacent first rectangular cross-section damping layer 46.

[0047] The method 200 advances to block 208 and includes the step of printing, by the three-dimensional printer or printing system 110 , in a single print, a rib 36 having at least two ribbon layers 40 , 42 of ribbon material and a layer 46 of damping material sandwiched between the layers 40 , 42 of ribbon material.

[0048] Thus, the ribs 36 and thoracic cage assembly 16 of the present disclosure have more anatomical ribs 36 than ever before. By taking advantage of 3D printing of two dissimilar materials in a single print, the ribs 36 can have enhanced hysteresis or damping properties, making the ribs 36 more anatomical than ever before.

[0049] Next, refer to Figures 7 to 12 , provides Figure 3-Figure 4 The improved exemplary embodiment of one of the ribs 36 of the thoracic component 16 shown in FIG. 1 includes one or more strain gauges 100 coupled thereto, and the coupled strain gauges 100 are used to Figure 3-Figure 4 The rib 36 is converted into Figure 7-12In these embodiments, the modified rib 136 can be Figure 7-12 In the drawings, the ribs are additionally labeled as modified full ribs 136A or modified half ribs 136B (in addition to being labeled as full ribs 36A, half ribs 36B, or simply ribs 36). Similar to ribs 36, the term "modified ribs 136" specifically encompasses "modified full ribs 136A" or "modified half ribs 136B."

[0050] exist Figure 7 In the embodiment, it is shown that substantially corresponds to Figure 3-Figure 4 The modified full rib 136A is shaped like the embodiment of the full rib 36A shown in FIG, but does not show the apertures 48 therethrough that allow for the introduction of fasteners to connect the unmodified full rib 36 of the thorax assembly 16 to the crash test dummy 12. Figure 7 In FIG, a pair of strain gauges 100 (one visible and one shown in phantom) are included that have been printed (i.e., three-dimensionally printed) onto the outer surface 41 of the front strip layer 40 of the strip material of the full rib 36A to form a modified full rib 136A. However, the electronics for electrically coupling the strain gauges 100 to the controller 199 for evaluating the strains occurring on the modified full rib 136A during the crash test simulation are omitted. Figure 7 In FIG. 4 , the rib 36 is three-dimensionally printed as a single strip 40 of material, but similarly represents the rib 36 having a pair of strip layers 40 , 42 and no damping layer 46 .

[0051] exist Figure 8 In the embodiment of FIG, one rib 36 is shown as a half rib 36B configured for connection to the crash test dummy 12 within the thorax assembly 16, with the half rib 36B corresponding to the right or left side of the crash test dummy 12. Figure 9 middle, Figure 8 The half-rib 36B has been modified to include one or more three-dimensional printed strain gauges 100 that have been printed (ie, three-dimensionally printed) onto the outer surface 41 of the front ribbon layer 40 of ribbon material to form a modified half-rib 136B.

[0052] exist Figures 8-10 In the embodiment of FIG. 1 , an aperture 48 is included through the half-rib 36B, 136B at either end thereof to allow for the introduction of fasteners to attach the half-rib 36B, 136B of the thoracic assembly 16 to a position on the crash test dummy 12 corresponding to the right or left side of the crash test dummy 12. Figure 10-12 In the embodiment of the present invention, the half-ribs 36B, 136B are provided as including a front strip layer 40 and a rear strip layer 42 separated by an interior space 44 that is not filled with damping material 46, but in alternative embodiments the interior space may be filled with damping material to form a damping layer 46 as described above.

[0053] Each corresponding strain gauge 100 (such as Figure 10 The length l and width w of the modified rib 136 (shown in FIG) are determined in part based on the length and width of the rib 36 to which the strain gauge 100 is applied, combined with the desired area of ​​the modified rib 136 where strain will be measured during a crash test simulation. In this way, measurements of the actual strain levels in the desired area of ​​the underlying, unmodified rib 36 covered with strain gauges 100 can be obtained instantly during a specific crash simulation, more closely resembling the performance of an actual human rib under the same crash test simulation conditions. Furthermore, because the modified rib 136 comprises a 3D-printed component (i.e., the underlying 3D-printed rib 36 and the 3D-printed strain gauge 100), the strain of the modified rib 136 can be measured during repeated crash test simulations.

[0054] exist Figures 9-12 In the embodiment of FIG. 1 , a modified half rib 136B is shown comprising a plurality of strain gauges 100 printed onto the outer surface 41 of the front ribbon layer 40 of the ribbon material, wherein Figure 10-12 Also shown are a pair of weld joints 120 that introduce electrical connections at either end (ie, first end 103 and second end 105 ) of each respective printed strain gauge 100 .

[0055] also, Figure 11 and Figure 12 Also shown is a wiring harness 140 ( Figure 11 and Figure 12 140) along the outer surface 41 of the front ribbon layer 40 with the ends of the wires 145 electrically connected to the corresponding solder joints 120. In some embodiments, as well as Figure 11 As shown, adhesive tape 135 is positioned over a portion of wiring harness 140 (and optionally also over strain gauge 100 (also as shown). Figure 11 ) to couple the wire harness 140 outwardly relative to the corresponding strain gauge 100 along the outer surface 41 of the front ribbon layer. The wires 145 of the wire harness 140 are configured to couple to the controller 199 at the respective wire ends opposite to the ends connected to the weld joint 120. Figure 11 A second set of wires 145 extending from the second strain gauge 100 is also shown, but the wiring harness 140 and its connection to the controller 199 are omitted.

[0056] also, Figure 11 Also shown are bolts 130 located proximate the rear belt layer 42 for coupling corresponding modified half-ribs 136B of the thoracic assembly 16 to the crash test dummy 12 .

[0057] Furthermore, in Figures 8-11In the embodiment, the rib 36 is formed with a pair of strip layers 40, 42 but without the damping layer 46, so that the strip layers 40, 42 define a cavity (corresponding to the first rectangular cross-section RCL1) between the opposite ends 46A, 46B. Figure 3 FIG. 4 shows RCL1 with the damping layer 46 present).

[0058] In another embodiment of the present invention, one or more strain gauges 100 may be coupled to the outer surface of the three-dimensional printed rib 36 via a polymer sheet 150 to form a modified rib 136 .

[0059] In such Figure 12 In one exemplary embodiment shown, the strain gauge 100 is three-dimensionally printed onto the front surface 151 of a polymer sheet 150 that is coupled to a corresponding unmodified full rib 36A to form a modified half rib 136A. The polymer sheet 150 has an adhesive backing (shown in phantom as 152) bonded to a rear surface 153 opposite the front surface 151 thereof. The adhesive backing 152 is bonded to the outer surface 41 of the front ribbon layer 40 of the ribbon material of each rib 36 ( Figure 12 The ribs 36 , 36A are shown without the single ribbon layer 42 and without the damping layer 46 . Figure 12 Also shown are a pair of weld joints 120 that introduce electrical connections at either end of a corresponding one of the printed strain gauges 100. In certain embodiments, the polymer sheet 150 is a polyester film (such as Mylar®).

[0060] also, Figure 12 Schematic diagram illustrating the coupling of a wire harness 140 adjacent to the outer surface 41 of the front tape layer 40 to the ends of wires 145 electrically connected to corresponding welded joints 120. Specifically, adhesive tape 135 is positioned over a portion of the wire harness 140 to couple the wire harness 140 outwardly relative to the corresponding strain gauges 100 and polymer sheet 150 along the outer surface 41 of the front tape layer 40. The wires 145 of the wire harness 140 are configured to be coupled to a controller 199.

[0061] exist Figure 7-12 In each of the respective embodiments of the present invention, the strain gauge 100 defines an integrated sensor, wherein the strain gauge 100 is formed to include equally spaced rows 101 of conductive material that are applied directly to the outer surface of the rib 36 or to the sheet 150 as described above and electrically connected in a serpentine configuration between a first end 103 and a second end 105. Thus, a series of 90-degree bends 107 connect each adjacent row 101 between the first end 103 and the second end 105 (see FIG. Figure 10The thickness of each row 101 and each bend 107 is sufficient to provide uniform electrical conductivity between the first end 103 and the second end 105. The spacing between parallel rows 101 is sufficient to avoid electrical connection between the rows between the bends 107.

[0062] In this serpentine configuration and also as Figure 10 As shown, the length l of each strain gauge 100 is defined as the distance between the bends 107 connecting adjacent rows 100, and the width w of each strain gauge 100 is defined as the distance between two protruding points that are most distant in a direction orthogonal to the length.

[0063] In an exemplary embodiment, strain gauge 100 is applied directly to the outer surface of rib 36 or applied to rib 36 via polymer sheet 150 using a 3D printing technique similar to that used to form modified rib 136 described above.

[0064] As described above, the strain gauge 100 is formed of a conductive material and can be formed by Figure 7 The conductive material is applied using a 3D printer or printing system similar to the 3D printer or printing system 110 shown in FIG. In particular, 3D printers capable of applying the conductive material to form the strain gauge 100 into the rows 101 with bends 107 as described above are preferred and include 3D printers commercially available from nScrypt's 3Dn series printers from nScrypt, Inc. of Orlando, Florida, USA.

[0065] In some embodiments, the viscosity of the conductive material ranges from 1 centipoise to more than 1 million centipoise. The conductive material preferably comprises conductive particles (e.g., silver) dispersed in a polymer material, or may be in the form of nanoparticle silver ink, which may be substantially as described above. Figure 8 The technique described in

[15] , but modified to accommodate printing of conductive materials, is applied using nScrypt's 3Dn series printer program. The thickness of the rows 101 and bends 107 should be sufficient to allow electrical charge to pass through the rows 101 and bends 107 between the first end 103 and the second end 105 of the strain gauge 100.

[0066] In such Figure 7 、 Figure 9 、 Figure 10 and Figure 11 In the embodiment shown, the strain gauge 100 is printed onto the outer surface of the curved component (ie, the rib 36). Figure 6 The three-dimensional printing process described is initiated to print the strain gauge 100 while the component is held in place in a desired orientation by the three-dimensional printer or printing system 110. Figure 12In the embodiment of the present invention, the polymer sheet 150 is positioned on the base of the 3D printer or printing system 110 and held in place, and then Figure 6 A three-dimensional printing process is described to print the strain gauge 100 .

[0067] In each embodiment, after the strain gauges 100 applied to the ribs 36 to form the modified ribs 136 are electrically coupled to a controller 199 via corresponding wiring harnesses 140 (these strain gauges define an integrated sensor), the crash test dummy 12 can be evaluated in a crash test simulation to determine component performance characteristics that closely match the performance of the corresponding component in the human body under similar crash scenarios. Specifically, the controller 199 can measure the displacement of each modified rib 136 in the lateral and forward directions during the crash simulation, which can last from 10 milliseconds to 200 milliseconds, by measuring changes in the electrical signals from the strain gauges 100. The data obtained for components such as the ribs 36 can then be used to optimize the component relative to the human body, and thus, to optimize the safety systems in the vehicle, in an attempt to minimize harm to the human body in a resulting crash.

[0068] Reference Figure 13 The present disclosure provides a method 500. According to various embodiments of the present disclosure, the method includes the step of coupling electrical components to the strain gauge 100 based on manufacturing a three-dimensionally printed modified rib 136 for a crash test dummy 12, so that the formed modified rib 136 with the strain gauge 100 can be used for repeatable testing in a crash test simulation, which will be described in Figure 16 below.

[0069] Method 500 begins at bubble 502 and proceeds to block 504. Figure 6 In block 504 of block 204 of FIG. 504 , method 500 includes the step of providing a three-dimensional printer or printing system 110. Method 500 proceeds to block 506 , which corresponds to Figure 6 The method 500 proceeds to block 508 corresponding to the step of generating a first CAD model of the rib 36. In one embodiment, the first CAD model of the rib 36 is made to allow the 3D printer to print the rib 36 in one go. Figure 8 2 and includes the steps of printing, by a 3D printer or printing system 110, ribs 36 in a single print pass using at least two ribbon layers 40, 42 of ribbon material and a layer 46 of damping material (i.e., damping layer 46) sandwiched between the ribbon layers 40, 42. In some alternative embodiments, ribs 36 are formed without damping layer 46.

[0070] Next, method 500 proceeds to block 510 or block 512 .

[0071] At block 510, method 500 continues with the step of printing the strain gauge 100 directly onto the outer surface of the rib 36 using a 3D printer using 3D printing technology in a desired pattern and with a desired overall width and length, thereby forming the modified rib 136 having the strain gauge defining the integrated sensor. In some embodiments, the 3D printer used in block 510 is nScrypt's 3Dn series printer, available from nScrypt, Inc. of Orlando, Florida, USA. In some embodiments, the strain gauge 100 is printed directly onto the outer surface of the first ribbon layer 40 or the second ribbon layer 42 of the rib 36.

[0072] As an initial part of the steps of block 510 , the user identifies a location along the interior or exterior of the rib 36 , such as a particular location of the first ribbon layer 40 or the second ribbon layer 42 along the rib 36 .

[0073] In particular, by Figure 7 A three-dimensional printer or printing system like the illustrated three-dimensional printer or printing system 110 applies the conductive material to the outer surface of the ribs 36 (or to the outer surface of the first ribbon layer 40 or the second ribbon layer 42 of the ribs 36).

[0074] As part of the steps of block 510, Figure 8 Prior to the illustrated three-dimensional printing process to print the strain gauge 100 , the ribs 36 are held in place in a desired orientation by a three-dimensional printer or printing system 110 .

[0075] In some embodiments, the step of printing the strain gauge 100 in step 510 occurs sequentially with the step of printing the three-dimensional rib 36 in step 508. Specifically, the strain gauge 100 may be printed onto a portion of the rib 36 after the rib 36 has been formed in step 508 but before step 508 is completed, and the remaining portion of the rib 36 may be three-dimensionally printed after the three-dimensional printing of part or all of the strain gauge 100. In other words, steps 508 and 510 may be performed in a coordinated manner to continuously three-dimensionally print the rib 36 and the strain gauge 100.

[0076] In other embodiments, the step of printing the strain gauge 100 in step 510 occurs after the step of printing the three-dimensionally printed rib 36 in step 508 .

[0077] exist Figure 7-11 In the embodiment of FIG, the rib 36 is held in place prior to the three-dimensional printing process described in block 510 so that the strain gauge 100 can be printed onto the front exterior surface 41 of the rib 36. Once printing is complete, the printed strain gauge 100 defines the sensor.

[0078] In block 512 , in an embodiment where the strain gauge 100 is applied to the rib 36 via the polymer sheet 150 , the method 500 continues and includes the following steps: printing the strain gauge 100 directly onto the front surface 151 (i.e., the first surface 151 ) of the polymer sheet 150 using a 3D printer using 3D printing technology.

[0079] The polymer sheet 150 may include adhesive previously applied to the opposing rear surface 153 (ie, second surface 153 ) of the polymer sheet 150 , or the method may proceed to block 514 where the adhesive backing 152 is applied to the second surface 153 of the polymer sheet 150 .

[0080] exist Figure 12 In the embodiment of the present invention, the polymer sheet 150 is positioned on the base of the 3D printer or printing system 110 and fixed in place, and then the following steps are performed: Figure 6 The three-dimensional printing process is described to print the strain gauge 100 onto the front surface 151 of the polymer sheet 150. Once printing is complete, the printed strain gauge 100 defines a sensor.

[0081] In block 514, polymer sheet 150 is coupled to the surface of rib 36 to form modified rib 136. Specifically, adhesive backing 152 is pressed into adhesive contact with the surface of rib 36 such that adhesive backing 152 is positioned between strain gauge 100 and the surface of rib 36.

[0082] In certain embodiments, the adhesive backing 152 is pressed into adhesive contact with a surface of one of the tape layers 40 , 42 of the rib 36 at a desired location such that the adhesive backing 152 is positioned between the strain gauge 100 and the surface of the rib 36 to form the modified rib 136 .

[0083] Next, in step 516 , the wires 145 of the wiring harness 140 are electrically coupled to the respective ends 103 , 105 of the strain gauge 100 coupled to the rib 36 .

[0084] Finally, in step 518 , the wires 145 of the wiring harness are electrically coupled to the controller 199 , and the modified rib 136 is thus ready for crash test simulation.

[0085] Now refer to Figure 14 , which provides the basis for the evaluation Figure 13 Related method 600 of forming the modified rib 136 .

[0086] Method 600 begins at bubble 602 and proceeds to block 604. In block 604, Figure 13The method is prepared to include positioning the modified rib 136 electrically coupled between the controller 199 and the strain gauge 100 and preferably to the wires 145 of the wiring harness 140 of the crash test dummy 12 at the desired location of the crash test simulator.

[0087] Next, as indicated by block 606, the crash test dummy 12 is subjected to a sudden impact, which causes strain in the integrated sensor / strain gauge 100 corresponding to the location on the 3D-printed rib 36 within a very short time span (i.e., the moment of the impact simulation), specifically, a time span of 10 milliseconds to 200 milliseconds, for example, 50 milliseconds when the applied force exceeds 7000 Newtons or 60 milliseconds when the applied force exceeds 3500 Newtons. This deformation causes strain on the strain gauge 100, resulting in some areas being stretched and other areas being compressed. Furthermore, the rib 136 and the strain gauge 100 undergo repeated deformation. The strain on the integrated sensor / strain gauge 100 (in terms of both tension and compression) causes a change in the electrical signal in the strain gauge 100 that is sensed by the controller 199, where the electrical signal is transmitted from the strain gauge 100 through the welded joint 102 and to the controller 199 via the wires 145 of the wiring harness 140.

[0088] Next, as indicated by block 608, the controller 199 utilizes the computer program and various algorithms contained within the computer program to interpret the changes in the electrical signal from the strain gauge 100 that occur during the 10 millisecond to 200 millisecond period of the crash test simulation, thereby determining the strain on the rib 36 at the location corresponding to the strain gauge 100 during each 10 millisecond to 200 millisecond time period of the crash test simulation.

[0089] Notably, due to the use of the 3D printed rib 36 and the strain gauge 100 , the same modified rib 136 can be repeatedly tested or evaluated under the same or different crash test conditions to determine the repetitive impact response to the human rib, as shown in block 610 .

[0090] The present disclosure has been described in an illustrative manner.It is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation.

[0091] Many modifications and variations of the present disclosure are possible in light of the above teachings. Accordingly, the present disclosure may be practiced in other ways than specifically described.

Claims

1. A method for manufacturing a 3D printed rib and a 3D printed strain gauge for a crash test dummy, the method comprising the following steps: Provide 3D printers; generating a first CAD model of the three-dimensional printed rib for the crash test dummy; generating a second CAD model of the three-dimensional printed strain gauge for the crash test dummy; Printing, by the 3D printer, the 3D printed rib having an outer surface formed of a polymer material based on the first CAD model; as well as The 3D printed strain gauge is directly formed on the outer surface of the 3D printed rib from conductive metal ink by the 3D printer based on the second CAD model to define an integrated sensor on the 3D printed rib, so that during a crash test in which the 3D printed rib is subjected to a sudden impact and causes the integrated sensor to generate strain within a time span of 10 to 200 milliseconds, the integrated sensor detects strain in the 3D printed rib.

2. The method according to claim 1 , wherein the step of printing, by the 3D printer, the 3D printed rib having an outer surface formed of a polymer material based on the first CAD model comprises: generating a first CAD model of the 3D printed rib for the crash test dummy, wherein the first CAD model of the 3D printed rib forms a first rectangular cross-section comprising a damping layer sandwiched between two ribbon layers, the first rectangular cross-section extending along an axis perpendicular to the first rectangular cross-section to form an arcuate length terminating at opposite ends, and each of the opposite ends forming a second rectangular cross-section comprising a single ribbon layer without a damping layer, the single ribbon layer extending along the axis away from the first rectangular cross-section damping layer; as well as The first CAD model is printed by the 3D printer using a strip material to form the strip layer and printing the first CAD model using a damping material to form the damping layer, wherein the strip layer has an outer surface.

3. The method according to claim 2, wherein the step of printing the three-dimensional strain gauge on the surface of the three-dimensional component based on the second CAD model by the three-dimensional printer comprises: The three-dimensional strain gauge is directly formed by conductive metal ink on the outer surface of one of the two strip layers by the three-dimensional printer based on the second CAD model to define an integrated sensor on the three-dimensional printed rib, so that during a collision test in which the three-dimensional printed rib is subjected to a sudden impact and causes the integrated sensor to generate strain within a time span of 10 to 200 milliseconds, the three-dimensional printed rib with the integrated sensor detects the strain in the three-dimensional printed rib.

4. The method according to claim 1 , wherein the step of printing, by the 3D printer, the 3D printed rib having an outer surface formed of a polymer material based on the first CAD model comprises: generating a first CAD model of the 3D printed rib for the crash test dummy, wherein the first CAD model of the 3D printed rib forms a first rectangular cross-section including two ribbon layers defining a cavity therebetween, the first rectangular cross-section extending along an axis perpendicular to the first rectangular cross-section to form an arcuate length terminating at opposite ends, and each of the opposite ends forming a second rectangular cross-section including a single ribbon layer without the cavity, the single ribbon layer extending along the axis away from the first rectangular cross-section damping layer; and The first CAD model is printed by the 3D printer using a strip material to form the strip layer, wherein the strip layer has an outer surface.

5. The method according to claim 4, wherein the step of printing the three-dimensional strain gauge on the surface of the three-dimensional component based on the second CAD model by the three-dimensional printer comprises: The three-dimensional strain gauge is directly formed by conductive metal ink on the outer surface of one of the two strip layers by the three-dimensional printer based on the second CAD model to define an integrated sensor on the three-dimensional printed rib, so that during a collision test in which the three-dimensional printed rib is subjected to a sudden impact and causes the integrated sensor to generate strain within a time span of 10 to 200 milliseconds, the three-dimensional printed rib with the integrated sensor detects the strain in the three-dimensional printed rib. 6 . The method according to claim 1 , wherein the step of printing the three-dimensional strain gauge and the step of printing the three-dimensional printed rib are performed continuously.

7. A crash test dummy comprising: main body; a spinal assembly operatively attached to the subject; a thoracic assembly coupled to the spinal assembly, the thoracic assembly having a plurality of three-dimensionally printed ribs formed of a polymer material, each rib having an outer surface; as well as A 3D printed strain gauge is formed from a conductive metal ink directly on the outer surface of one of the plurality of 3D printed ribs to define an integrated sensor on the one 3D printed rib, wherein the 3D printed strain gauge is configured to detect strain in the one 3D printed rib when the one 3D printed rib is subjected to a sudden impact within a time span of 10 to 200 milliseconds.

8. The crash test dummy of claim 7 , wherein the at least one 3D printed rib forms a first rectangular cross-section comprising a damping layer sandwiched between two ribbon-like layers, the first rectangular cross-section extending along an axis perpendicular to the first rectangular cross-section to form an arcuate length terminating at opposite ends, and each of the opposite ends forming a second rectangular cross-section comprising a single ribbon-like layer without a damping layer, the single ribbon-like layer extending along the axis away from the first rectangular cross-section damping layer.

9. The crash test dummy of claim 7 , wherein the at least one three-dimensionally printed rib forms a first rectangular cross-section comprising two ribbon-like layers defining a cavity therebetween, the first rectangular cross-section extending along an axis perpendicular to the first rectangular cross-section to form an arcuate length terminating at opposite ends, and each of the opposite ends forming a second rectangular cross-section comprising a single ribbon-like layer without the cavity, the single ribbon-like layer extending along the axis away from the first rectangular cross-section damping layer.

10. The crash test dummy of claim 7, further comprising: Controller; as well as a wiring harness comprising one or more wires electrically coupling the three-dimensional printed strain gauge to the controller, The controller is configured to determine a change in the strain of the 3D printed rib by corresponding changes in the 3D printed strain gauge when the 3D printed component is subjected to the sudden impact within the time span of 10 to 200 milliseconds.

11. The crash test dummy of claim 10, further comprising a solder joint for electrically coupling the three-dimensional printed strain gauge to the one or more wires.

12. A system for forming a three-dimensional printed part for a crash test dummy, the three-dimensional printed part having a three-dimensional printed strain gauge coupled thereto, the system comprising: 3D printers; as well as A controller coupled to the 3D printer and configured to: generating a first CAD model of the three-dimensional printed part for the crash test dummy; generating a second CAD model of the three-dimensional printed strain gauge for the crash test dummy; Printing, by the 3D printer, the 3D printed component having an outer surface formed of a polymer material based on the first CAD model; as well as The 3D printed strain gauge is formed directly on the outer surface of the 3D printed component from a conductive metal ink by the 3D printer based on the second CAD model to define an integrated sensor on the 3D printed component, so that the integrated sensor detects strain in the 3D printed component during a crash test in which the 3D printed component is subjected to a sudden impact that causes the integrated sensor to generate strain within a time span of 10 to 200 milliseconds.

13. The system of claim 12, wherein the three-dimensional printed component comprises three-dimensional printed ribs, wherein the controller of the system is configured to: generating the first CAD model of the 3D printed rib for the crash test dummy, wherein the first CAD model of the 3D printed rib forms a first rectangular cross-section comprising a damping layer sandwiched between two ribbon layers, the first rectangular cross-section extending along an axis perpendicular to the first rectangular cross-section to form an arcuate length terminating at opposite ends, and each of the opposite ends forming a second rectangular cross-section comprising a single ribbon layer without a damping layer, the single ribbon layer extending along the axis away from the first rectangular cross-section damping layer; and The three-dimensional printed rib having an outer surface and formed of a polymer material is printed by the three-dimensional printer based on the first CAD model.

14. The system of claim 12, wherein the three-dimensional printed component comprises three-dimensional printed ribs, wherein the controller of the system is configured to: generating the first CAD model of the 3D printed rib for the crash test dummy, wherein the first CAD model of the 3D printed rib forms a first rectangular cross-section including two ribbon layers defining a cavity therebetween, the first rectangular cross-section extending along an axis perpendicular to the first rectangular cross-section to form an arcuate length terminating at opposite ends, and each of the opposite ends forming a second rectangular cross-section including a single ribbon layer without the cavity, the single ribbon layer extending along the axis away from the first rectangular cross-section damping layer; and The three-dimensional printed rib having an outer surface and formed of a polymer material is printed by the three-dimensional printer based on the first CAD model.

15. A system for producing a three-dimensional component for a crash test dummy, the three-dimensional component having a strain gauge coupled thereto, the three-dimensional printed strain gauge being configured to detect strain in the three-dimensional printed component during a crash test in which the three-dimensional printed component is subjected to a sudden impact that causes the three-dimensional printed component to strain within a time span of 10 to 200 milliseconds, the system comprising: 3D printers; as well as A controller coupled to the 3D printer and configured to: generating a first CAD model of the three-dimensional component for the crash test dummy; generating a second CAD model of the three-dimensional strain gauge for the crash test dummy; Printing the first CAD model of the three-dimensional component by the three-dimensional printer; providing a polymer sheet having a front surface and an opposing back surface; as well as printing the second CAD model of the three-dimensional strain gauge onto the front surface of the polymer sheet by the three-dimensional printer; Wherein the polymer sheet is subsequently coupled to the three-dimensional component such that the polymer sheet is disposed between the three-dimensional component and the three-dimensional strain gauge.

16. The system of claim 15, wherein the three-dimensional printed component comprises a three-dimensional printed rib, wherein the controller of the system is configured to: generating the first CAD model of the 3D printed rib for the crash test dummy, wherein the first CAD model of the 3D printed rib forms a first rectangular cross-section comprising a damping layer sandwiched between two ribbon layers, the first rectangular cross-section extending along an axis perpendicular to the first rectangular cross-section to form an arcuate length terminating at opposite ends, and each of the opposite ends forming a second rectangular cross-section comprising a single ribbon layer without a damping layer, the single ribbon layer extending along the axis away from the first rectangular cross-section damping layer; and The three-dimensional printed component having an outer surface and formed of a polymer material is printed by the three-dimensional printer based on the first CAD model.

17. The system of claim 15, wherein the three-dimensional printed component comprises three-dimensional printed ribs, wherein the controller of the system is configured to: generating the first CAD model of the 3D printed rib for the crash test dummy, wherein the first CAD model of the 3D printed rib forms a first rectangular cross-section including two ribbon layers defining a cavity therebetween, the first rectangular cross-section extending along an axis perpendicular to the first rectangular cross-section to form an arcuate length terminating at opposite ends, and each of the opposite ends forming a second rectangular cross-section including a single ribbon layer without the cavity, the single ribbon layer extending along the axis away from the first rectangular cross-section damping layer; and The three-dimensional printed rib having an outer surface and formed of a polymer material is printed by the three-dimensional printer based on the first CAD model.

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