Claims:WE CLAIM:
1. A fixture for fatigue testing of bush to plate weld assembly comprising a support plate (3) mounted with a sample (1, 2), wherein top portion of the support plate (3) is accommodated inside upper grip (6a) of dynamic testing machine and lower portion of the support plate (3) goes into lower grip (6b) of the dynamic testing machine, in which the sample (1, 2) is secured to a push-pull rod (5).

2. The fixture for fatigue testing of bush to plate weld assembly as claimed in claim 1, wherein the lower portion of the support plate (3) constitutes widest part.

3. The fixture for fatigue testing of bush to plate weld assembly as claimed in claim 1 or 2, wherein the support plate (3) has a plurality of holes (H) for fastening of the sample therewith and an integral claw (3a) to provide additional grip to the sample.

4. The fixture for fatigue testing of bush to plate weld assembly as claimed in claims 1-3, wherein the sample includes a base plate (1) to which bush (2) is welded by fillet joint.

5. A fixture for fatigue testing of bush to plate weld assembly as claimed in claim 1-4, wherein the rod (5) is fastened to the bush (2) by a fastener (4) passing through hole (5a) in the rod (5).

6. The fixture for fatigue testing of bush to plate weld assembly as claimed in claim 1-5, wherein the wider part of the rod (5) is accommodated inside lower grip (6b) of the machine by gripping to the lower grip of the machine.

7. A fixture for fatigue testing of bush to plate weld assembly as claimed in claim 1-6, wherein the top portion of the plate (3) gets grip to the upper grip (6a) of said testing machine.
, Description:A fixture for fatigue testing of bush to plate weld assembly
FIELD OF INVENTION
[001] The present invention is directed to a fixture for fatigue testing of bush to plate weld assembly. Thus, the present invention relates to a fixture and a method of use of the fixture to fatigue test a bush-to-plate assembly in a cantilever beam arrangement to assess the strength of the fillet weld between the bush and the plate.

BACKGROUND OF THE INVENTION

[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] Load-carrying fillet welds frequently occur in welded structures such as shell structures, ships and offshore installations, bridges, cranes etc. Typical examples are cruciform joints, bush to plate/shell joints where fatigue cracks may initiate not only from the weld toe, but also from the non-fused root face. A fatigue assessment of the latter is possible using for example the nominal stress in the weld throat. However, load-carrying fillet welds are in certain structures much more subjected to throat bending, which increases the risk of root failure, for example at connections with one-sided fillet welds or cover plates subjected to out-of-plane loads.

[004] There is conventional dynamic testing equipment available world vide to perform fatigue testing of standard samples. In all these conventional testing, loading is provided uniaxial or in single plane. But for the present application as the requirement is testing of a cantilever beam arrangement, the loading should be out of plane or eccentric. For this purpose, a fixture has been fabricated which can make use of the same conventional dynamic testing machine and can provide an eccentric loading.

[005] In view of the above, the present invention has been introduced.

OBJECTS OF THE INVENTION

[001] An object of the invention is to propose a fixture for fatigue testing of bush to plate weld assembly.
[002] Another object of the invention is to propose a fixture for fatigue testing of bush to plate weld assembly which is simple in construction.
[003] Still another object of the present invention is to provide a fixture for fatigue testing of bush to plate weld assembly which causes loading in the toe of the fillet weld and can provide an eccentric loading.
[004] These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.

SUMMARY OF THE INVENTION

[005] One or more drawbacks of conventional systems and process are overcome, and additional advantages are provided through the apparatus and a method 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 part of the claimed disclosure.
[006] According to the present invention, a fixture is designed to facilitate the fatigue testing of fillet welded bush to a shell plate joint. The bush acts as a load carrying member inside the annular portion of the shell plate. In a free body diagram, the assembly acts as a cantilever beam with bush fixed to the shell plate and a point load acts at the end of the bush. The load in fact is not static here, it is fluctuating or dynamic in nature. In order to determine the life of the assembly in the presence of dynamic load, the assembly needs to be tested in an existing dynamic test machine setup. Hence, a fixture is fabricated to apply the dynamic/fatigue load at the end of the bush with the shell being a fixed member.

[007] Accordingly, there is provided a fixture for fatigue testing of bush to plate weld assembly comprising a support plate mounted with a sample, wherein top portion of the support plate is accommodated inside upper grip of dynamic testing machine and lower portion of the support plate goes into lower grip of the dynamic testing machine, in which the sample is secured to a push-pull rod.

[008] The lower portion of the support plate constitutes widest part.

[009] The support plate has a plurality of holes for fastening of the sample therewith and an integral claw to provide additional grip to the sample.

[010] The sample includes a base plate to which bush is welded by fillet joint.

[011] The rod is fastened to the bush by a fastener passing through hole in the rod.

[012] The wider part of the rod is accommodated inside lower grip of the machine by gripping to the lower grip of the machine.

[013] The top portion of the plate gets grip to the upper grip of said testing machine.

[014] 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.

[015] 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.

[016] 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 ACCOMPANYING DRAWINGS
[017] The illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and processes that are consistent with the subject matter as claimed herein, wherein:-

Figure 1 shows: Bush-to-plate fillet welded assembly (sample).
Figure 2 shows: Support plate for mounting the sample.
Figure 3 shows: Push-pull rod.
Figure 4 shows: The comprehensive view of a fixture for fatigue testing of bush to plate weld assembly in accordance with present invention.
[018] The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily 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.

DETAIL DESCRIPTION OF THE PRESENT INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS OF PREFERRED EMBODIMENTS
[019] 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.
[020] The present invention pertains to a technology relating to a fixture for fatigue testing of bush to plate weld assembly.

? Fig 1: bush-to-plate fillet welded assembly (sample) includes the following:

1 – The shell plate
2 – The bush which is welded to the shell plate

? Fig 2: Support plate for mounting the sample involves the following:

3 – The support plate
3a – An integral part of support plate which serves as a claw to support the sample
9b- Bolt to fasten the sample to left side shoulder clamps

? Fig 3: Push-pull rod comprises the following features:

5- Push-pull rod with a hole in the top of the rod.

? Fig 4: The comprehensive view of the assembly has the following features:

1- The shell plate
2- The bush which is welded to the shell plate
3- The support plate
3a- An integral part of support plate which serves as a claw to support the sample
4- Bolt used to tighten the sample with item 5
5- Push-pull rod with a hole in the top of the rod
6a- The upper grip of the dynamic testing machine
6b- The lower grip of the dynamic testing machine.

[021] The fixture of present invention is employed for testing sample as illustrated in figure 1. The sample comprises a base plate (1) (also interchangeably referred to as shell plate here) to which bush (2) is welded using fillet joint. The purpose of present invention is to test the sample in fatigue loading and asses the life of the fillet joint between the bush (2) and shell plate (1). The loading is to be done in such a way that the sample acts as a cantilever beam and the load is concentrated in the toe of the weld joint. The fixed end of the cantilever forms the weld joint and the free end of the cantilever is where loading is done. Now referring to Figure 2 showing the support plate (3) for mounting the sample. This comprises of a plurality of holes to facilitate fastening of the sample to the support plate. The support plate also has an integral claw (3a) to provide additional grip. The top portion of the support plate (3) gets grip to the upper grip of the conventional dynamic testing machine (6a, figure 4).
[022] Now, reference may be made to Figure 3 showing the push-pull rod (5) with a hole (5a) to accommodate a bolt. The widest part of plate (3) goes into the lower grip of the conventional dynamic testing machine (6b, figure 4), wherein Figure 4 shows the complete assembly of the fixture used to fatigue test the bush-to-plate sample (figure 1). The sample is supported and fastened to the support plate (3) using four bolts and the claw (3a) and the set up as such is gripped to the upper grip the dynamic testing machine (6a). The push-pull rod is then fastened to the bush (2) using a bolt and the wider part of the push pull rod (5) is gripped to the lower grip of the dynamic testing machine.
[023] As our requirement demands for an eccentric loading, the developed fixture serves the purpose efficiently. Thus, allowing the test to be carried out successfully. Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.

[024] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.

[025] Advantageous features of Fixture:-

- Simple in construction and portable in nature.
- Purely mechanical in nature and requires no maintenance
- Can be used in any dynamic testing machine.

[026] 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 particulars 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 bare 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 analogues 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”.
[027] The above description does not provide specific details of manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.

[028] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.

[029] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.

[030] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.