Description:ANTI-TWISTING DEVICE FOR HOLDING THIN METAL SHEET DURING SHEAR TESTING
FIELD OF INVENTION:
[001] The present subject matter described herein, relates to metal testing technology to test shear loading on thin metal sheets. In particular, the present invention relates to an anti-twisting device for holding thin metal sheet and preventing out-plane twisting of the metal sheet during shear testing.
BACKGROUND AND PRIOR ART AND PROBLEM IN PRIOR ART:
[002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[003] In current modern world, thin metal sheets are used at many places, such as automobile bodies (commercial as well as personal), airplane fuselages and wings, medical tables, roofs for buildings (architecture) and many other applications. In the automobile industry, safety and reliability of the automobile is prime concern where shear loading sustainability of the metal sheets plays important role for safety and reliability of the automobile.
[004] Automotive applications, such as crash testing of B-pillars, crash box etc. require an ability to withstand shear loading during its functioning. These applications also involve components with thin steel sheet. Adaption of these thin sheets is result of extensive need of automotive sector to reduce vehicle weight, a characteristic which is inevitable. To facilitate use of thin sheet material, it is also essential to characterize shear properties of the same. Shear testing asks for a mechanical assembly/adjustment wherein the out-of-plane twisting can be prevented as well as the strain measurement can also be facilitated.
[005] In the existing anti-twisting devices, there are several challenges and dis-advantages. The existing anti-twisting devices require large number of parts which need to be join with each other through complicated joining mechanisms. Assembly of large number of parts increases cost, weight of device and time of assembly, further, there are high chances of failure of any part during use, accordingly, the existing anti-twisting device has less durability and high serviceability. Another disadvantage associated with the existing anti-twisting device are high weight, high cost and with high probability of loss of small parts. Also, the existing devices do not have the provision of clamping it on one of the surface of the sheet sample at the gauge section and get the strain of the sample during the experiment.
[006] Therefore, there is a need to develop an Anti-twisting device which can be used for shear testing of sheet metal by overcoming the above-mentioned technical problems. There is a need in the art to have a design and structured Anti-twisting device which is cost effective and simple in structure to avoid twisting of thin sheet in the shear testing.
[007] The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
[008] OBJECTS OF THE INVENTION:
[009] It is therefore the object of the present disclosure to overcome the aforementioned and other drawbacks in prior device/system/apparatus.
[0010] The principal objective of the present disclosure is to provide an anti-twisting device to be used for preventing twisting of thin metal sheet during shear testing process.
[0011] Another object of the present disclosure is to provide the anti-twisting device to prevent out-plane twisting of the metal sheet during shear testing.
[0012] Yet another object of the present disclosure is to provide the anti-twisting device which is cost efficient, easy to manufacture, have lesser number of parts, and avoids out-plane twisting of thin metal sheet during shear testing of the sheet.
[0013] Still another object of the present disclosure is to provide the anti-twisting device that can be clamped on the surface of the metal sheet and shear strain during experiment.
[0014] These and other objects and advantages of the present subject matter will be apparent to a person skilled in the art after consideration of the following detailed description taken into consideration with accompanying drawings in which preferred embodiments of the present subject matter are illustrated.
SUMMARY OF THE INVENTION:
[0015] One or more drawbacks of conventional anti-twisting device for shear testing of thin metal sheet are overcome, and additional advantages are provided through the anti-buckling device as claimed in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be a part of the claimed disclosure.
[0016] The present subject matter relates to an anti-twisting device for a shear testing of thin sheet metal. The anti-twisting device comprises of two I-shaped sections where each of the two identical plates has an identical circular slot which is provided at the center of the each of the I-shaped section. A through hole is provided on each of the two I-shaped section at four sides to mount the one I-shaped section over the other I-shaped section by a plurality of fasteners. From the four through holes, two through holes are provided at the top portion and other two are provided at the bottom horizontal plate of each of I-shaped section. The through holes at one I-shaped section is aligned with the corresponding through holes at the other I-shaped section. The two I-shaped sections are fastened together by fastening means, preferably, nut-bolt mechanism with specimen metal sheet sandwiched in between the two I-shaped sections.
[0017] In an embodiment, a circular slot is provided at the center of each of the two I-section to mark a point on the specimen metal sheet during sheer testing.
[0018] In an embodiment, an obround circular hole is defined at each of upper end and lower end of the specimen metal sheet.
[0019] In an embodiment, the obround holes defined at the specimen metal sheet allows for stretching out the specimen metal sheet while shear testing.
[0020] In an embodiment, the width of vertical plates of I-shaped sections is greater than the width of the specimen steel sheet such that the fastened I-shaped sections completely covers the specimen metal sheet.
[0021] In an embodiment, the metal sheet thickness ranges from 0.55 mm to 0.7 mm.
[0022] In an embodiment, Hardness of I-shaped sections is more than that of metal sheet specimen.
[0023] In an embodiment, Hardness of the metal sheet is less than that of I-shaped section.
[0024] In an embodiment, the metal sheet is made up of High strength quality (HSQ) steel.
[0025] In an embodiment, the I-shaped section is made up of metal harder than HSQ steel.
[0026] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.
[0027] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods or structure in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which:
[0029] Fig. 1 illustrates exploded isometric view of all the components of the anti-twisting device and a specimen steel sheet.
[0030] Fig. 2 illustrates sequence of assembly/attachment of the anti-twisting device.
[0031] Fig. 3 illustrates a front view of the device assembly showing the circular slit at the center of the one of the I-shaped section of the device.
[0032] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS:
[0033] While the embodiments of the disclosure are subject to various modifications and alternative forms, specific embodiment thereof have been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.
[0034] The terms “comprises”, “comprising”, or any other variations thereof used in the disclosure, are intended to cover a non-exclusive inclusion, such that a device, system, assembly that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such system, or assembly, or device. In other words, one or more elements in a system or device proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or device.
[0035] The present subject matter relates to an anti-twisting device for preventing twisting of a thin metal sheet during shear testing of the sheet. It is focused to prevent out-plane twisting of the metal sheet during shear testing process. Four through holes are provided on each of the two I-shaped sections to mount the one I-section over the other I-section by a plurality of fasteners. Two of the through out of four through holes are provided at the top horizontal plate and the two through holes are provided at the bottom horizontal plate of each of the I-shaped section. The two I-shaped section are fastened together by fastening means, preferably nut-bolt mechanism.
[0036] It should be noted that the description and figures merely illustrate the principles of the present subject matter. It should be appreciated by those skilled in the art that conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present subject matter. It should also be appreciated by those skilled in the art that by devising various arrangements that, although not explicitly described or shown herein, embody the principles of the present subject matter and are included within its spirit and scope. Furthermore, all examples recited herein are principally intended expressly to be for pedagogical purposes to aid the reader in understanding the principles of the present subject matter and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. The novel features which are believed to be characteristic of the present subject matter, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures.
[0037] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope.
[0038] In the present specification, arrow marked with XX indicates width direction and arrow marked with YY’ indicates longitudinal direction.
[0039] Fig. 1 illustrates a structure of anti-twisting device 100 to prevent out-plane twisting of a thin metal sheet during shear testing, in accordance with an embodiment of the present subject matter. The ant-twisting device 100 comprises of two I-shaped section 101a and 101b. Both the I-shaped sections 101a,101b are preferably identical but it is not necessarily required. Each of the I-shaped section from the two I shaped sections 101a, 101b comprises two horizontal plates longitudinally joined by a vertical plate to define the I shaped section. Further, width of horizontal plates in XX’ direction is more than width of the vertical plate in XX’ direction. A circular slit or slot 105a, 105b is provided at center of the vertical plate of each of the I-shaped sections. Further, each of the two I-shaped sections 101a, 101b has two through holes 102a, 103a at left hand side of top horizontal plates; two through holes 102b, 103b at the right hand side of the top horizontal plates; two through holes 102c, 103c at the left hand side of the bottom horizontal plate and the two through holes 102d, 103d at the right hand side of the bottom horizontal plate.
[0040] The plurality of through holes 102a, 102b, 102c, 102d on one of the I-shaped section is aligned to the plurality of corresponding through holes 103a, 103b, 103c, 103d provided at the other I-shaped section. The two I-shaped sections 101a, 101b are fasten with each other by a plurality of nuts 113a, 113b, 113c, 113d and bolts 112a, 112b, 112c, 112d.
[0041] Furthermore, Fig.1 shows a specimen metal sheet 111 on which shear testing is to be performed. The specimen metal sheet 111 is to be sandwiched between the two I-shaped sections 101a, 101b during shear testing to prevent out-plane twisting of the specimen metal sheet 111. The width of vertical plates of each of two I-shaped sections 101a, 101b are greater than width of the specimen metal sheet 111 such that the two I-shaped sections 101a, 101b completely covers the width of the specimen metal sheet 111. Further, material of the anti-twisting device 100 is stronger than material of the metal sheet 111. In an exemplary embodiment, the metal sheet 111 thickness ranges from 0.55 mm to 0.7 mm.
[0042] In an embodiment, Hardness of I-shaped sections 101a, 101b is more than that of metal sheet specimen. The hardness of the metal sheet is less than that of I-shaped section. The metal sheet is made up of High strength quality (HSQ) steel. The I-shaped section is made up of metal harder than HSQ steel.
[0043] Two obround holes 111a, 111b are defined at each upper end and lower end of the specimen metal sheet 111. The obround holes 111a and 111b are provided to apply strain on the specimen metal sheet 111 by stretching out the specimen metal sheet 111 from both ends, i.e., upper end and lower end.
[0044] Referring to Fig. 2, it shows steps to assemble or attach the two I-sections 101a, 101b of the anti-twisting device 100 with the specimen metal sheet 111 sandwiched in between the two I-shaped sections 101a, 101b. At step 1, the two I-shaped section 101a, 10b are placed apart with the specimen metal sheet 111 in between. At step 2, the two I-shaped section 101a, 101b are placed together in close proximity that through holes 102a,102b provided at the top horizontal plate of the one of the I-shaped section 110a align with the corresponding through holes 103a, 103b provided at the other I-shaped section 110b. And the through holes 102c, 102d provided at the bottom horizontal plate of the one of the I-shaped section 110a align with the corresponding through holes 103c, 103d provided at the other I-shaped section 110b. At step 3, the two I-shaped sections 101a, 101b are fastened together with a specimen metal sheet 111 sandwiched in between.
[0045] In a preferred embodiment, as shown in Fig. 1, nuts 113a, 113b, 113c, 113d and bolt 112a, 112b, 112c, 112d mechanism is employed to fasten the two I-shaped sections 101a,101b together such that the specimen metal sheet 111 is secured tightly and is unable to get displaced or twisted from the secured position while the shear force is applied to it during shear testing. The I-shaped sections 101a, 101b kept in such a way that their profile gets superimposed or matches over each other. The I-shaped section 101a, 101b are fastened such that the bolt and nut can be easily unclamped through hand without using any tool. The I-shaped sections 101a, 101b should not be fastened loose or tight. For experimental/testing result, proper fastening of the identical plates 101a, 101b is very essential.
[0046] In reference to Fig. 3 that illustrates front view of fastened I-shaped sections 101a with the specimen metal sheet 111 sandwiched in between I-shaped section 101a and 101b. The circular slot 105a, provided at the center of the each of I-shaped sections 101a, and specimen metal sheet 111 is sandwiched in such manner that the center point of the specimen metal sheet aligns with the circular slots 105a, 105b provided at each of the I-shaped section 101a, 101b. The shear strain experienced by the specimen metal sheet 111, for example; is maximum at its center point. Therefore, the circular slot 105a, 105b is to be preferably defined at the center of I-shaped section 101a, 101b so that the strain can be calculated effectively. The circular slot 105a, 105b facilitates to mark point on the specimen metal sheet 111 before applying strain and after applying strain on the specimen steel sheet 111. The shear strain of the specimen metal sheet 111 is calculated by finding out displacement of marked point i.e. Point marked before applying strain and its final position after applying strain. The point marked through the circular slot 105a after applying the strain provides reference of initial position of point marked before applying strain as the specimen metal sheet 111 is tightly secured by the anti-twisting device 100and unable to get twisted or displaced.
Advantages of the Invention over prior art:
[0047] The present structure of Anti-twisting device prevents twisting of thin metal sheet during shear testing of the metal sheet and facilitates to mark points on the thin metal sheet to measure the displacement of the marked point and get sensed or scanned or detected by a DIC instrument
[0048] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the plate recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances, where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”
[0049] It will be further appreciated that functions or structures of a plurality of components or steps may be combined into a single component or step, or the functions or structures of one-step or component may be split among plural steps or components. The present invention contemplates all of these combinations. Unless stated otherwise, dimensions and geometries of the various structures depicted herein are not intended to be restrictive of the invention, and other dimensions or geometries are possible. In addition, while a feature of the present invention may have been described in the context of only one of the illustrated embodiments, such feature may be combined with one or more other features of other embodiments, for any given application. It will also be appreciated from the above that the fabrication of the unique structures herein and the operation thereof also constitute methods in accordance with the present invention. The present invention also encompasses intermediate and end products resulting from the practice of the methods herein. The use of “comprising” or “including” also contemplates embodiments that “consist essentially of” or “consist of” the recited feature.
[0050] Although embodiments for the present subject matter have been described in language specific to structural features, it is to be understood that the present subject matter is not necessarily limited to the specific features described. Rather, the specific features and methods are disclosed as embodiments for the present subject matter. Numerous modifications and adaptations of the system/component of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the scope of the present subject matter.

Claims:We claim:
1. An anti-twisting device (100) for holding a thin metal sheet (111) during shear testing, the anti- twisting device (100) comprising:
two identical I-shaped sections (101a, 101b), each of the I-shaped section from the two identical I-shaped section (101a, 101b) comprising two horizontal plates longitudinally joined by a vertical plate from at center point of the two horizontal plates to define the I-shaped section;
a through hole (102a, 102b, 102c, 102d, 103a, 103b, 103c, 103d) provided at left hand side and right hand side of the top horizontal plates and the bottom horizontal plates of each of the two I-shaped sections (101a, 101b); and
a circular slot (105a 105b) provided at center of each of the vertical plate of the two I- shaped sections (101a, 101b), wherein the circular slot (105a, 105b) facilitates marking point on the metal sheet (111) during shear testing.
2. The anti-twisting device (100) as claimed in claim 1, wherein the through holes (102a, 102b) provided at the top horizontal plate of the I-shaped section (101a) are aligned with the corresponding through holes (103a, 103b) provided at the top horizontal plate of the second I-shaped section (101b).
3. The anti-twisting device (100) as claimed in claim 1, wherein the through holes (102c, 102d) provided at the bottom horizontal plate of the I-shaped section (101a) are aligned with the corresponding through holes (103c, 103d) provided at the bottom horizontal plate of the second I-shaped section (101b).
4. The anti-twisting device (100) as claimed in claim 1, wherein the two identical I-shaped sections (101a, 101b) are fastened by a plurality fastener at the through holes (102a, 102b, 102c, 102d and 103a, 103b, 103c, 103d) provided at the two I-shaped sections (101a, 101b).
5. The anti-twisting device (100) as claimed in claim 1, wherein the plurality of fastener are nut and bolts.
6. The anti-twisting device (100) as claimed in claim 1, wherein the metal sheet (111) is sandwiched in between the two I-shaped sections (101a, 101b) during shear testing.
7. The anti-twisting device (100) as claimed in claim 1, wherein the width of vertical plates of I-shaped sections (101a, 101b) is greater than the width of the metal sheet (111) such that the fastened I-shaped sections completely covers the metal sheet (111).
8. The anti-twisting device (100) as claimed in claim 1, wherein material of the anti-twisting device (100) is stronger than material of the metal sheet (111).
9. The anti-twisting device (100) as claimed in claim 1, wherein the metal sheet thickness ranges from 0.55 mm to 0.7 mm.
10. The anti-twisting device (100) as claimed in claim 1, wherein Hardness of I-shaped sections (101a, 101b) is more than that of metal sheet specimen.
11. The anti-twisting device (100) as claimed in claim 1, wherein Hardness of the metal sheet is less than that of I-shaped section.
12. The anti-twisting device (100) as claimed in claim 1, wherein the metal sheet is made up of High strength quality (HSQ) steel.
13. The anti-twisting device (100) as claimed in claim 1, wherein the I-shaped section is made up of metal harder than HSQ steel.