A four-point bend fatigue testing fixture with a large span of up to two meters

Abstract

A four-point bend fatigue test assembly includes a beam (102). The load is transferred from a bottom-mounted actuator to a beam. A first support assembly (104) and a second support assembly (108) are arranged to transfer the load from the beam (102) to a specimen (106). A third support assembly (110) is coupled to a load-measuring unit and rigidly holds the specimen (106). A fourth support assembly (114) and a fifth support assembly (116) are rigidly coupled below the first support assembly (104) and second support assembly (108), respectively and house the beam (102). A sixth support assembly (144) is operatively coupled to the actuator of the load frame and rigidly holds the beam (102). The assembly (100) facilitates the testing of large specimens (106) of span lengths within a range between 0.5 meters and 2 meters against bend fatigue loading at a frequency of up to 8 Hertz.

Description

TECHNICAL FIELD

[0001] The present disclosure relates, in general, to experimental mechanics. More particularly, it relates to a four-point bend fatigue test assembly.BACKGROUND

[0002] The background description includes information that may be useful in understanding the present disclosure. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed disclosure, or that any publication specifically or implicitly referenced is prior art.

[0003] Large structures are often subjected to cyclic loading, so they often fail under fatigue during their use or service. The evaluation of material under bending fatigue becomes essential for determining safe limits of operational life. Common examples of such large structures include beams, railway weld joints and others. The joints, such as welding, and discontinuity in the structure raise stress around them. The evaluation of the structural integrity of these structures has become a critical factor. Testing specimens at a coupon level and extrapolating the same at the component scale can predict the safe life of the structure to a certain extent. However, this may not be accurate; a state of art setup is needed to test the structures by simulating the same loading environment as they experience during application.

[0004] A few efforts have been made in the below-mentioned applications to mitigate the above problem at the laboratory coupon level. In patent publication no. CN217688377U, a four-point bend fatigue test setup was developed for a multi-layer pultrusion plate. However, the above patent application had limitations as this setup can only be used for the bend fatigue test on smaller plates and cannot be used for large structures. A further limitation is that the setup can only be used for compression-compression loading conditions.

[0005] In a patent publication no. CN215339321U, a three-point / four-point bending fatigue testing device for composite material is disclosed. This setup includes a lower support and an upper anvil where a span length can be varied, and a load application is from the upper anvil. However, the above patent application had limitations as the device cannot be used for metal structures with large span lengths. Moreover, it was developed such that an actuator is placed at the upper anvil and cannot be used for tension-compression loading.

[0006] In a patent publication no. JP06839383B2, a four-point bending fatigue-test jig, a fatigue-test apparatus, and an acceleration deterioration test method are disclosed. This can be used for testing thin sheets using the four-point bend fatigue test method. A tool for testing fatigue has an inner pin holding unit with a pair of lower-side inner pin and an upper-side inner pin and a movement unit that fixes the inner pin holding unit. A fixation unit has a pair of outer lower side pins and outer upper side pins. The movable unit is movable in vertical direction with respect to the fixation unit. A force sensor and an actuator are located at the top and the bottom is fixed. However, the above patent application had limitations as the setup is not suitable for large span lengths structures.

[0007] In a patent publication no. CN112557181B, a clamp for four-point bending and four-point shearing fatigue of rock concrete is disclosed. This clamp can only be used for rock concrete for realizing four-point bend fatigue and four-point shear fatigue with positive and negative stress ratios as per the claim. The details about the placement of the actuator are not available in the disclosure. Moreover, the above patent application had limitations as the clamp cannot be used for testing large structures.

[0008] In a patent publication no. CN107917844A, a three-point and four-point bend fatigue test tool for the composite material is disclosed. This setup can be used for three-point as well as the four-point bend fatigue test for thin sheets. The fixture can adjust the clamping width and clamping thickness of the specimen size of different bending fatigue test standards and has good versatility. This utility model cannot be used for large span lengths structures.

[0009] In a patent publication no. IN202011016480A, a device for conducting three-point and four-point flexural fatigue strength of a specimen is disclosed. This device can be used for applying cyclic alternating and reversal bending stresses on the specimen. However, the above patent application had limitations as the device cannot be used for testing large metallic structures.

[0010] In a patent publication no. CN218098610U, a two-way four-point bend fatigue test fixture is disclosed. The setup comprises a transmission structure, a clamp assembly, a stressed support, and a fixing device. This test setup is designed for four-point bend fatigue testing. This setup is capable of applying bidirectional loading on tests specimens with variable thickness. However, the above patent application had limitations as the above setup cannot be used to test structures with large span lengths.

[0011] There is, therefore, a requirement in the art to overcome the above-mentioned problems by providing a simple, compact, efficient, and cost-effective assembly for a four-point bend fatigue test for beams with a maximum span length of up to two meters on a bottom-mounted actuator load frame.OBJECTS OF THE INVENTION

[0012] A general object of the present disclosure is to overcome the problems associated with existing four-point bend fatigue testing devices, by providing a simple, compact, efficient, and cost-effective four-point bend fatigue test assembly to test large structures up to two meters against four-point bend fatigue loading on a bottom-mounted actuator load frame.

[0013] Another object of the present disclosure is to provide an assembly wherein the load is applied from the bottom-mounted actuator to the outer support of the specimen with the reaction forces being generated at the inner supports.

[0014] Yet another object of the present disclosure is to provide an assembly for testing four-point bend fatigue on structures of lengths ranging between 0.5 meters to 2 meters.

[0015] Yet another object of the present disclosure is to provide an assembly to simulate tension-tension, tension-compression, and compression-compression cyclic loadings at a sinusoidal frequency of up to 8 Hertz.SUMMARY

[0016] Aspects of the present disclosure pertain to a four-point bend fatigue test assembly.

[0017] In an aspect, the four-point bend fatigue test assembly includes a beam. The load from the bottom-mounted actuator is transferred to the beam. The beam includes a left end and a right end. The assembly includes a first support assembly. The first support assembly is configured to transfer a first load from the beam to a first end of a specimen. The assembly includes a second support assembly. The second support assembly is configured to transfer a second load from the beam to a second end of the specimen. In addition, the assembly includes a third support assembly. The third support assembly is operatively coupled to a load-measuring unit. The third support assembly is configured to hold the specimen rigidly. The third support assembly rigidly supports a portion between the first end and the second end of the specimen. The assembly includes a fourth support assembly. The fourth support assembly is rigidly coupled below the first support assembly. The fourth support assembly is configured to house the left end of the beam. The first load is applied on the first support assembly to facilitate bend fatigue loading on the specimen. Further, the assembly includes a fifth support assembly. The fifth support assembly is rigidly coupled below the second support assembly. The fifth support assembly is configured to house the right end of the beam. The second load is applied on the second support assembly to facilitate bend fatigue loading on the specimen. The sixth support assembly is operatively coupled to an actuator of a load frame and is configured to rigidly hold the beam.

[0018] The assembly is configured to apply the bend fatigue loads to the specimen. The load is applied on the line of action of the rollers at the outer span while providing rigid support on the line of action of the rollers at the inner span. The assembly facilitates the testing of large specimens of span length within a range of 0.5 meters to 2 meters to perform high frequency (≤ 8 Hertz) cyclic tests.

[0019] The assembly is configured to facilitate tension-tension, tension-compression, and compression-compression loadings at a sinusoidal frequency on the specimen.

[0020] In an embodiment, the first support assembly may include a first top flange plate. The first top flange plate may be parallelly suspended against a first bottom flange plate by a plurality of first stud bolts to house the first end of the specimen.

[0021] In an embodiment, the first top flange plate may include at least one first top roller. The first bottom flange plate may include at least one first bottom roller and one first symmetric block. The specimen may be positioned between the at least one first top roller and the at least one first bottom roller.

[0022] In an embodiment, the second support assembly may include a second top flange plate. The second top flange plate may be parallelly suspended against a second bottom flange plate by a plurality of second stud bolts to house the second end of the specimen.

[0023] In an embodiment, the second top flange plate may include at least one second top roller. The second bottom flange plate may include at least one second bottom roller and one second symmetric block. The specimen may be positioned between the at least one second top roller and the at least one second bottom roller.

[0024] In an embodiment, the third support assembly may include a couple of third flange plates. The couple of third flange plates may be parallelly suspended against each other by a plurality of third stud bolts to rigidly house the specimen. The at least one third flange plate of the couple of third flange plates may be coupled to the load measuring unit.

[0025] In an embodiment, each third flange plate may include a plurality of third rollers. The plurality of third rollers may be positioned between the specimen and each third flange plate.

[0026] In an embodiment, the fourth support assembly. The fourth support assembly may include a fourth flange plate. The fourth flange plate may be parallelly suspended below the first bottom flange plate. The fourth flange plate by a plurality of fourth stud bolts to house the left end of the beam.

[0027] In an embodiment, the fifth support assembly may include a fifth flange plate parallelly suspended below a second bottom flange plate by a plurality of fifth stud bolts to house the right end of the beam.

[0028] In an embodiment, the assembly may include a sixth support assembly. The sixth support assembly may be configured on the portion between the left end and the right end of the beam. The sixth support assembly may include a couple of sixth flange plates. The couple of sixth flange plates may be parallelly suspended against each other by a plurality of sixth stud bolts. The couple of sixth flange plates may house the portion between the left end and the right end of the beam. The at least one sixth flange plate of the couple of sixth flange plates may be coupled to the actuator of the load frame.

[0029] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.BRIEF DESCRIPTION OF FIGURES

[0030] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0031] FIG. 1 is a schematic view of a four-point bend fatigue test assembly, in accordance with an embodiment of the present disclosure.

[0032] FIG. 2 is a side view of a four-point bend fatigue test assembly, in accordance with an embodiment of the present disclosure.

[0033] FIG. 3 is a schematic view of a specimen housed within a first support assembly and a second support assembly of the four-point bend fatigue test assembly, in accordance with an embodiment of the present disclosure.

[0034] FIG. 4 is a schematic view of a beam housed within a fourth support assembly, a fifth support assembly, and a sixth support assembly of the four-point bend fatigue test assembly, in accordance with an embodiment of the present disclosure.

[0035] FIG. 5 is a schematic view of a third support assembly of the four-point bend fatigue test assembly, in accordance with an embodiment of the present disclosure.

[0036] FIG. 6 is a schematic view of the specimen within the four-point bend fatigue test assembly, in accordance with an embodiment of the present disclosure.

[0037] Skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the drawings may be exaggerated relative to other elements to help to improve understanding of embodiments of the present disclosure.DETAILED DESCRIPTION

[0038] The one or more shortcomings of the prior art are overcome by the system as disclosed, and additional advantages are provided through the provision of the system as disclosed in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the disclosure.

[0039] The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

[0040] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and / or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore,such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

[0041] Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[0042] The use of the expression "at least" or "at least one" suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

[0043] Any discussion of documents, acts, materials, devices, articles and the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.

[0044] The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher / lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.

[0045] Spatially relative terms, such as "under", "below", "lower", "over", "upper", "top", "bottom" and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the FIGS. It will be understood that the spatially relative terms areintended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the FIGS. For example, if the device in the figures is turned over, elements described as "under" or "beneath" other elements or features would then be oriented "over" the other elements or features. Thus, the exemplary term "under" can encompass both an orientation of over and under. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0046] Herein, the terms "attached", "connected", "interconnected", "contacting", "mounted", "coupled" and the like can mean either direct or indirect attachment or contact between elements, unless stated otherwise.

[0047] Well-known functions or constructions may not be described in detail for brevity and / or clarity. As used herein the expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0048] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises", "comprising", "includes" and / or "including" when used in this specification, specify the presence of stated features, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, operations, elements, components, and / or groups thereof.

[0049] Embodiments explained herein relate to a simple, compact, efficient, and cost effective four-point bend fatigue test assembly.

[0050] Various embodiments of the present disclosure will be explained in detail with reference to FIGs. 1-6.

[0051] Referring to FIGs. 1 to 6, in an aspect, the four-point bend fatigue test assembly (hereinafter referred to as "assembly 100", herein) is disclosed. According to an aspect, the assembly 100 includes a beam 102. The beam 102 includes a left end 102-1 and a right end 102-2. In addition, the assembly 100 includes a first support assembly 104, a second support assembly 108, a thirdsupport assembly 110, a fourth support assembly 114, and a fifth support assembly 116. The assembly 100 is configured to facilitate tension-tension load, tension-compression load, and compression-compression load cyclic loadings at a predefined sinusoidal frequency on a specimen. The predefined sinusoidal frequency may be between a range of 1 Hertz to 8 Hertz. The specimen 106 may be between a range of 0.5 meters to 2 meters. In an exemplary embodiment, the specimen can be selected from a group consisting of, but not limited to, the beam, a column, a plate, a shell, a composite, and concrete specimens.

[0052] In an embodiment, the first support assembly 104 can transfer a first load from the beam 102 to a first end 106-1 of the specimen 106. The first end 106-1 of the specimen 106 can be housed within the first support assembly 104. In addition, the first support assembly 104 may include a couple of first flange plates 118. A first top flange plate 118-1 may be parallelly suspended against a first bottom flange plate 118-2 by a plurality of first stud bolts 120. The first top flange plate 118-1, the first bottom flange plate 118-2, and the plurality of first stud bolts 120 may define the first support assembly 104. The first support assembly 104 may house the first end 106-1 of the specimen 106. Furthermore, the first top flange plate 118-1 may include at least one first top roller 122-1, and the first bottom flange 118-2 may include at least one first bottom roller 122-2 and one first symmetric block 150. The specimen 106 may be positioned between the at least one first top roller 122-1 and the at least one second bottom roller 122-2.

[0053] In an embodiment, the second support assembly 108 can transfer a second load from the beam 102 to a second end 106-2 of the specimen 106. The second end 106-2 of the specimen 106 may be housed within the second support assembly 108. In addition, the second support assembly 108 may include a second top flange plate 124-1 and a second bottom flange plate 124-2. The second top flange plate 124-1 may be parallelly suspended against the second bottom flange plate 124-2 by a plurality of second stud bolts 126. The second top flange plate 124-1, the second bottom flange plate 124-2, and the plurality of second stud bolts 126 may define the second support assembly 108. The second support assembly 108 may house the second end 106-2 of the specimen 106. Furthermore, the secondtop flange plate 124-1 may include at least one second top roller 128-1, and the second bottom flange plate 124-2 may include at least one second bottom roller 128-2 and one second symmetric block 152 such that the specimen 106 may be positioned between the at least one second top roller 128-1 and the at least one second bottom roller 128-2.

[0054] In an embodiment, the third support assembly 110 can be operatively coupled to a load measuring unit. The third support assembly 110 can rigidly hold the specimen 106. A portion between the first end 106-1 and the second end 106-2 of the specimen 106 can be housed within the third support assembly 110. The third support assembly 110 may rigidly support the specimen 106. The assembly 100 may enable the beam 102 to apply bend fatigue loading from the actuator on the specimen 106. In addition, the third support assembly 110 may include a couple of third flange plates 130. The couple of third flange plates 130 may be parallelly suspended against each other by a plurality of third stud bolts 132. The couple of third flange plates 130 and the plurality of third stud bolts 132 may rigidly house the specimen 106. The at least one third flange plate of the couple of third flange plates 130 may be coupled to the load measuring unit. Furthermore, each third flange plate may include a plurality of third rollers 134. The plurality of third rollers 134 may be positioned between the specimen 106 and each third flange plate 130.

[0055] In an exemplary embodiment, the load measuring unit can be selected from a group consisting of, but not limited to, a load cell, a strain gauge, a load pin, a load link, a load ring, and a weighing scale.

[0056] The load cells may be transducers that convert force into an electrical signal. The load cell may be configured in different types, including strain gauge load cells, hydraulic load cells, and capacitive load cells.

[0057] The strain gauge may be used to measure a strain (deformation) on an object subjected to force. They operate on the principle that the electrical resistance of a conductor changes when subjected to mechanical strain. The strain gauges can be used in conjunction with the load cells to measure force accurately.

[0058] The load pin may be specialized load measuring devices designed as load-bearing elements in structures or machinery. They can be installed in equipment such as cranes, hoists, and industrial machinery to directly measure the load applied to them.

[0059] The load link may be a load measuring device resembling a link or shackle. The load links are used for lifting and rigging applications. They can provide a direct measurement of the load applied to the link and are commonly used in crane operations and heavy lifting.

[0060] The load ring may be similar to load links but designed in a ring shape. They can be used in applications where the load needs to be evenly distributed across multiple points, such as in lifting beams and spreader bars.

[0061] The weighing scale may be used to measure the weight of the object or the load. They can be in various types, including platform scales, bench scales, and truck scales, and may be used in industries ranging from retail and food production to logistics and transportation.

[0062] In an embodiment, the fourth support assembly 114 can be rigidly coupled below the first support assembly 104. The fourth support assembly 114 can house the left end 102-1 of the beam 102. The first load may be applied on the first support assembly 104 to facilitate bend fatigue loading on the specimen 106. In addition, the fourth support assembly 114 may include a fourth flange plate 136 and the first bottom flange plate 118-2. The fourth flange plate 136 may be parallelly suspended below the first bottom flange plate 118-2 by a plurality of fourth stud bolts 138. The fourth flange plate 136, the first bottom flange plate 118-2, and the plurality of fourth stud bolts 138 may house the left end 102-1 of the beam 102.

[0063] In an embodiment, the fifth support assembly 116 may be rigidly coupled below the second support assembly 108. The fifth support assembly 116 can house the right end 102-2 of the beam 102. The second load may be applied on the second support assembly 108 to facilitate bend fatigue loading on the specimen 106. In addition, the fifth support assembly 116 may include a fifth flange plate 140 parallelly suspended below the second bottom flange plate 124-2by a plurality of fifth stud bolts 142. The fifth flange plate 140, the second bottom flange plate 124-2, and the plurality of fifth stud bolts 142 may define the fifth support assembly 116. The fifth support assembly 116 may house the right end 102-2 of the beam 102.

[0064] In an embodiment, the assembly 100 may include a sixth support assembly 144 can be operatively coupled with the actuator of the load frame. The sixth support assembly 144 may be positioned on the portion between the left end 102-1 and the right end 102-2 of the beam 102. The sixth support assembly 144 may include a couple of sixth flange plates 146-1 and 146-2. The couple of sixth flange plates 146 may be parallelly suspended against each other by a plurality of sixth stud bolts 148. The couple of sixth flange plates 146 and the plurality of sixth stud bolts 148 may define the sixth support assembly 144. The sixth support assembly 144 may house the portion between the left end 102-1 and the right end 102-2 of the beam 102. The at least one sixth flange plate of the couple of sixth flange plates 146 may be coupled to the actuator of the load frame.

[0065] In an exemplary embodiment, a dynamic testing on large structures at different span lengths within the range between 0.5 meters to 2 meters was performed where several four-point fatigue bend tests on rail joints of length 2 meters under tension-compression, tension-tension, and compression-compression loadings were successfully applied at different load ratios, limited by the capacity of the existing fatigue testing machine (250 kN). The durability of the four-point bend fatigue test assembly had been successfully validated for more than 15000 hours of high-frequency (≤ 8 Hertz) cyclic loadings on the bottom-mounted actuator fatigue testing load frame. The tests had been conducted successfully without any major fault in the four-point bend fatigue test assembly except the weld joint of the rollers during the early stages. The design of the rollers and their integration with the fixture plates were then re-designed and successfully tested for nearly the same duration without any fault.

[0066] While considerable emphasis has been placed herein on the particular features of this disclosure, it will be appreciated that various modifications can be made, and that many changes can be made in the preferredembodiments without departing from the principles of the disclosure. These and other modifications in the nature of the disclosure or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.ADVANTAGES OF THE INVENTION

[0067] The present invention overcomes the problems associated with existing four-point bend fatigue testing devices, by providing a simple, compact, efficient, and cost-effective assembly for a four-point bend fatigue test of beams with a maximum span length of up to two meters on a bottom-mounted actuator load frame.

[0068] The present invention provides an assembly to apply load from the bottom-mounted actuator to the outer support of the specimen for testing against four-point bend fatigue loading on structures of span lengths ranging between 0.5 meters to 2 meters.

[0069] The present invention provides an assembly to simulate tension-tension, tension-compression, and compression-compression cyclic loadings at a sinusoidal frequency of up to 8 Hertz.

Claims

1. A four-point bend fatigue test assembly, the assembly (100) comprising: a beam (102) comprising a left end (102-1) and a right end (102-2); a first support assembly (104) configured to transfer a first load from the beam (102) to a first end (106-1) of a specimen (106) therewithin; a second support assembly (108) configured to transfer a second load from the beam (102) to a second end (106-2) of the specimen (106) therewithin; a third support assembly (110) operatively coupled to a load measuring unit and configured to rigidly hold the specimen (106) therewithin such that the third support assembly (110) rigidly supports a portion between the first end (106- 1) and the second end (106-2) of the specimen (106) enabling the beam (102) to apply bend fatigue loading on the specimen (106); a fourth support assembly (114) rigidly coupled below the first support assembly (104) and configured to house the left end (102-1) of the beam (102) such that the first load is applied on the first support assembly (104) facilitating bend fatigue loading on the specimen (106); a fifth support assembly (116) rigidly coupled below the second support assembly (108) and configured to house the right end (102-2) of the beam (102) such that the second load is applied on the second support assembly (108) facilitating bend fatigue loading on the specimen (106); and a sixth support assembly (144) operatively coupled to an actuator of a load frame and configured to rigidly hold the beam (102); wherein the assembly (100) is configured to apply the loads to the specimen (106) on a line of action of rollers (122, 128) at an outer span while providing a rigid support on the line of action of rollers (132) at an inner span on bottommounted actuating fatigue testing load frames for span lengths within a range between 0.5 meters to 2 meters to perform high frequency (≤ 8 Hertz) cyclic tests; and wherein the assembly (100) is configured to facilitate tension-tension, tension-compression, and compression-compression cyclic loadings at a predefined sinusoidal frequency on the specimen (106).

2. The assembly (100) as claimed in claim 1, wherein the first support assembly (104) comprises a first top flange plates (118-1) parallelly suspended against a first bottom flange plate (118-2) by a plurality of first stud bolts (120) to house the first end (106-1) of the specimen (106) therewithin.

3. The assembly (100) as claimed in claim 2, wherein the first top flange plate (118-1) comprises at least one first top roller (122-1), and the first bottom flange plate (118-2) comprises at least one first bottom roller (122-2) and one first symmetric block (150) such that the specimen (106) may be positioned between the at least one first top roller (122-1) and the at least one first bottom roller (122-2).

4. The assembly (100) as claimed in claim 1, wherein the second support assembly (108) comprises a second top flange plate (124-1) parallelly suspended against a second bottom flange plate (124-2) by a plurality of second stud bolts (126) to house the second end (106-2) of the specimen (106) therewithin.

5. The assembly (100) as claimed in claim 4, wherein the second top flange plate (124-1) comprises at least one second top roller (128-1), and the second bottom flange plate (124-2) comprises at least one second bottom roller (128-2) and one second symmetric block (152) such that the specimen (106) may be positioned between the at least one second top roller (128-1) and the at least one second bottom roller (128-2).

6. The assembly (100) as claimed in claim 1, wherein the third support assembly (110) comprises a couple of third flange plates (130) parallelly suspended against each other by a plurality of third stud bolts (132) to rigidly house the specimen (106) therewithin, wherein at least one third flange plate (130) of the couple of third flange plates (130) is coupled to the load measuring unit.

7. The assembly (100) as claimed in claim 6, wherein each third flange plate (130) comprises a plurality of third rollers (134) positioned between the specimen (106) and each third flange plate (130).

8. The assembly (100) as claimed in claim 1, wherein the fourth support assembly (114) comprises a fourth flange plate (136) parallelly suspended below a first bottom flange plate (118-2) by a plurality of fourth stud bolts (138) to house the left end (102-1) of the beam (102) therewithin.

9. The assembly (100) as claimed in claim 1, wherein the fifth support assembly (116) comprises a fifth flange plate (140) parallelly suspended below a second bottom flange plate (124-2) by a plurality of fifth stud bolts (142) to house the right end (102-2) of the beam (102) therewithin.

10. The assembly (100) as claimed in claim 1, wherein the assembly (100) comprises a sixth support assembly (144) configured on the portion between the left end (102-1) and the right end (102-2) of the beam (102), wherein the sixth support assembly (144) comprises a couple of sixth flange plates (146) parallelly suspended against each other by a plurality of sixth stud bolts (148) to house the portion between the left end (102-1) and the right end (102-2) of the beam (102) therewithin, and wherein at least one sixth flange plate (146) of the couple of sixth flange plates (146) is coupled to the actuator of the load frame.