WO2009027097A2

WO2009027097A2 - Sample analysis system

Info

Publication number: WO2009027097A2
Application number: PCT/EP2008/007094
Authority: WO
Inventors: Jürgen FRÖSCHL; Wilfried Eichlseder
Original assignee: Montanuniversität Leoben
Priority date: 2007-08-31
Filing date: 2008-08-29
Publication date: 2009-03-05
Also published as: EP2191251A2; WO2009027097A4; WO2009027097A3

Abstract

An apparatus for analyzing a sample, the apparatus comprising a first clamping chuck adapted for receiving a first portion of the sample, a second clamping chuck adapted for receiving a second portion of the sample, a drive unit adapted for applying a force to the first clamping chuck, and a measurement unit adapted for measuring at least one physical parameter indicative of a property of the sample received by the first clamping chuck and the second clamping chuck in response to the application of the force to the first clamping chuck, wherein the second clamping chuck is free of a separate drive unit.

Description

Sample Analysis System

The invention relates to an apparatus for analyzing a sample. The invention further relates to a method of analyzing a sample.

WO 2007/042275 discloses a method for checking a sample with combined rotational bending and torsional loading, preferably at high frequency, characterized by the combination of the following features: setting the sample in rotation, subjecting the sample to a torsional load by means of two torsional torques generated by electric motors applied to two opposing ends of the sample and subjecting the sample to a bending load either applied to the ends thereof or at a point between the ends.

For some applications, a sample analysis system having a simple construction may be desired.

It is an object of the invention to provide a sample analysis system which can be manufactured with reasonable effort.

In order to achieve the object defined above, a sample analysis system, and a method of analyzing a sample according to the independent claims are provided.

According to an exemplary embodiment of the invention, an apparatus for analyzing a sample is provided, the apparatus comprising a first clamping chuck adapted for receiving a first portion (for instance a first end portion) of the sample, a second clamping chuck adapted for receiving a second portion (for instance a second end portion) of the sample, a drive unit adapted for applying a force (particularly a drive force or a moment) to the first clamping chuck, and a measurement unit (such as a sensor) adapted for measuring at least one physical parameter indicative of a property of the sample received by the first clamping chuck and the second clamping chuck in response to the application of the force to the first clamping chuck, wherein the second clamping chuck is free of a separate drive unit (i.e. the apparatus may be devoid of additional drive units in addition to the single above mentioned drive unit). According to another exemplary embodiment of the invention, a method of analyzing a sample is provided, the method comprising receiving a first portion of the sample by a first clamping chuck, receiving a second portion of the sample by a second clamping chuck, applying a force to the first clamping chuck by a drive unit, and measuring at least one physical parameter indicative of a property of the sample received by the first clamping chuck and the second clamping chuck in response to the application of the force to the first clamping chuck, wherein the second clamping chuck is free of a separate drive unit.

According to still another exemplary embodiment of the invention, a program element (for instance a software routine, in source code or in computer-executable code) is provided, which, when being executed by a processor, is adapted to control or carry out a method of analyzing a sample having the above mentioned features.

According to yet another exemplary embodiment of the invention, a computer-readable medium (for instance a CD, a DVD, a USB stick, a floppy disk or a harddisk) is provided, in which a computer program is stored which, when being executed by a processor, is adapted to control or carry out a method of analyzing a sample having the above mentioned features. The test control scheme according to embodiments of the invention can be realized by a computer program, that is by software, or by using one or more special electronic optimization circuits, that is in hardware, or in hybrid form, that is by means of software components and hardware components. In the context of this application, the term "sample" may particularly denote any physical structure (particularly any technical apparatus, member, or a portion thereof) in the real world which may be under development or production or machining and shall therefore be investigated regarding its physical or economical properties such as mechanical stability, quality, usability, etc. Examples of such a physical structure may be a member or tool such as a cast or forged or moulded component. "Samples" may be complete products or semifinished parts, members made of electrically conductive or electrically insulating material, carbon fiber members, steel parts, etc.

The term "measurement device" may particularly denote any system capable of performing a measurement on the sample, that is to say for determining or sensing a parameter characterizing the sample in a specific scenario or under certain conditions such as an applied mechanical stress or load.

The term "property of the sample" may particularly denote technical information, features or attributes characterizing the result of the analysis of the sample, for instance a mechanical characterization.

According to an exemplary embodiment of the invention, a sample analysis system may be provided in which a sample clamped between two clamping chucks or collet chucks is driven by a single drive unit (that is to say there may be exactly one drive unit in the entire apparatus) by applying a force to one of the chucks. In the context of such a configuration, it is possible with a single drive unit and therefore with low effort to measure a physical parameter (such as torque and/or an torsion angle) with a simple construction and high accuracy.

Therefore, a variable concept for testing machines for torsion tests under static or cyclic, multiple stage torsion stress may be provided.

Such a test equipment may be constructed in a modular manner, and tests in or close to a resonance region of the system are possible. According to an exemplary embodiment of the invention, the turning angle of the sample under application of the force may be essentially unlimited, and the application of high static moments of rotation is possible with a static module. Thus, dynamic strength/vibration resistance experiments may be carried out, as well as static twisting experiments with a basically unlimited number of rotations. It is also possible to couple energy systems of multiple of such apparatuses to obtain a particularly efficient energy management. Furthermore, the costs for carrying out an analysis of a sample are very low with the simple construction of the apparatus according to an exemplary embodiment of the invention.

Next, further exemplary embodiments of the apparatus will be explained. However, these embodiments also apply to the method. The drive unit may comprise a servo drive, a combustion engine, a hydraulic drive, a synchronous machine, or an asynchronous machine. Drive units such as servo drives may be preferred which allow (due to their construction and/or drive characteristic) to rotate the sample with an unlimited rotation angle. The apparatus may comprise exactly one drive unit. Thus, according to an exemplary embodiment of the invention, no further drive units are foreseen at all in the apparatus apart from the drive unit for applying the force to the first clamping chuck. In other words, the entire driving system may be composed of or may be comprised of a single drive unit, rendering the apparatus small in construction and cheap in manufacture.

The measurement unit may be adapted for measuring the at least one physical parameter in a static manner, in a dynamic manner, or in a cyclic manner. Therefore, the performance of the apparatus covers many applications in very different technical fields, so that an analysis of different mechanical members is possible with a large freedom for a user.

The measurement unit may be adapted for measuring torque, an angle of torsion and/or a deformation behaviour. Particularly, the apparatus may measure one of such parameters at a time, for instance torque or an angle of torsion of a sample under analysis. However, alternatively, it is possible that two or more of such physical parameters are measured simultaneously, for instance torque and an angle of torsion. This may allow to obtain a powerful and highly accurate system. The first clamping chuck and/or the second clamping chuck may comprise a mechanically actuable clamping chuck or a hydraulically actuable clamping chuck. A mechanically actuable clamping chuck may be fixed at a sample by means of a mechanical or manual actuation of a user, for instance by turning an adjustment screw. Alternatively, a hydraulically actuable clamping chuck may use hydraulic forces to ensure reliable clamping of the sample, i.e. fastening of the sample at a groove of the chucks.

The first clamping chuck and/or the second clamping chuck may be mounted on the apparatus in a substitutable manner. Thus, many different clamping chucks in a modular system may be used which can be mounted in a replaceable manner on the apparatus by simply exchanging one component. This may allow to extend the field of possible applications of the apparatus, by adapting a used clamping chuck to the requirements of a specific analysis. Some kind of analysis construction set may be provided by taking such a measure.

The apparatus may comprise a set of a plurality of first clamping chucks and/or a set of a plurality of second clamping chucks differing regarding at least one property (such as size, maximum load, material, measurement units mounted in connection with a clamping chuck, etc.). Each of the set of clamping chucks may be mountable on the apparatus. Therefore, a modular system is provided which can be adapted specifically to the requirements of an embodiment.

The apparatus may comprise a spatially fixed first mount on which the first clamping chuck is mounted, and may comprise a spatially movable second mount on which the second clamping chuck is mounted. By spatially fixing the first mount, a stable configuration of this portion of the apparatus is enabled. However, by allowing a spatial movement of the second mount, sufficient flexibility can be provided to allow to take into account changes in an experimental set up during an experiment. For instance, a change of the temperature during operating the apparatus may change the geometric proportions of the apparatus due to thermal expansion. A spatially movable second mount may allow to compensate such modifications without the danger to involve additional parasitic stress components. For example, the spatially movable second mount may be slidable along a linear direction, enabling to adjust a distance to the spatially fixed, i.e. non moveable, first mount.

The apparatus may comprise a resonance adjustment module that may be adapted for adjusting the apparatus to operate in a resonance state. If it is possible to drive the apparatus in a resonance state, i.e. close to or exactly at an eigenfrequency of the system, the energy needed for driving or operating the apparatus may be reduced, resulting in an energy efficient operation of the apparatus, since losses may be very small when a resonance condition is fulfilled.

The resonance adjustment unit may be adapted for adjusting/controlling/regulating an operation frequency of the apparatus essentially to a resonance frequency. This may involve the automatic or user defined setting of the apparatus to operate at a resonance frequency of the system.

Additionally or alternatively, the resonance adjustment unit may enable an adjustment of a balance weight to bring the apparatus in the resonance state at a given frequency. For example, the balance weight may comprise a radially shiftable mass. By shifting the mass to a specific radial position, it is possible to modify the system eigenfrequency to thereby force the system to approach a resonance frequency of the system to an operation frequency of the system. This may allow to drive the apparatus into a resonance state even without adjusting the frequency, which may be cumbersome or involve additional energy consumption.

The apparatus may comprise a geometry adjustment unit adapted for adjusting a geometry of the apparatus in response to a change of a geometric property, particularly a thermally induced change of a length property. For instance, position sensors, distance sensors and/or temperature sensors may measure an expansion such as a thermal expansion of the driven apparatus. When it is determined that the configuration of the apparatus has been changed, the geometric properties (such as distances between different components of the apparatus, angular relations between different components of the apparatus, etc.) may be guided back into a desired state by the geometry adjustment unit. For example, the second mount may be moved slightly towards or away from the first mount when it is determined that a thermal expansion has altered the distance between the second mount and the first mount.

The apparatus may further comprise a harmonic drive arranged between the drive unit and the first clamping chuck. Such a harmonic drive may improve the operation of the apparatus and may allow for a proper transfer of the force from the drive unit to the sample.

The apparatus may comprise a coupling (for instance a clutch) between the drive unit and the first clamping chuck, which coupling may be stiff against torsion and bending elastic. Such a coupling may properly transfer the forces from the drive unit to the first clamping chuck. The stiffness against torsion and the bending elasticity of the coupling may allow to use the coupling without a negative impact on the accuracy of the analysis.

The second clamping chuck may be essentially spatially fixed, even upon application of a force to the first clamping chuck by the drive unit. Thus, torque and/or a twist angle of a sample may be measured in a state of the sample in which it remains essentially spatially fixed, apart from small material shifts within the sample due to the application of a force to the sample. According to an exemplary embodiment of the invention, a torsion experiment (which may or may not have an overlaid static moment) within or apart from a resonance may be carried out even with high torque, wherein the sample may rest, and only a simple drive may be sufficient. The servo drive implemented according to an exemplary embodiment of the invention may allow to provide up to 60 Nm or more, and in a resonance operation mode up to 120 Nm or more. As a gear, a harmonic drive may be advantageously implemented. Thus, according to an exemplary embodiment, a single axis torsion analysis concept for static or cyclic sample experiments may be provided. A variable test module may be provided, that is to say different modules may be employed in accordance with user preferences. The modules may be driven to a specific position of the system on a carriage. By performing a longitudinal length adjustment, artificial compression stress may be reduced or eliminated, for instance after warming up the system. The measured sample may have a dimension in the order of magnitude of, for example, 6 mm to 50 mm and may be provided with or without notches. It is also possible to measure wires or the like. When the system is operated in a resonance condition, an operation mode in or close to an energy minimum may be advantageously obtained, and essentially no losses occur in such a scenario. The aspects defined above and further aspects of the invention are apparent from the examples of embodiment to be described hereinafter and are explained with reference to these examples of embodiment.

The invention will be described in more detail hereinafter with reference to examples of embodiment but to which the invention is not limited.

Fig. 1 to Fig. 4 illustrate apparatuses for analyzing a sample according to exemplary embodiments of the invention. Fig. 5 to Fig. 7 illustrate different three-dimensional views of an apparatus similar to the apparatus of Fig. 3.

Fig. 8 illustrates a three-dimensional view of an apparatus according to an exemplary embodiment of the invention.

The illustration in the drawing is schematically. In different drawings, similar or identical elements are provided with the same reference signs.

In the following, referring to Fig. 1, an apparatus 100 for analyzing a sample 102 according to an exemplary embodiment of the invention will be explained.

The apparatus 100 comprises a first clamping chuck 104 adapted for receiving a first end of the sample 102. A second clamping chuck 106 is provided for receiving a second end of the sample 102. In the described embodiment, the first clamping chuck 104 and the second clamping chuck 106 are hydraulically actuable clamping chucks. A drive unit 108 is foreseen for applying a force at a first clamping chuck 104, and, in turn, to the sample 102. The drive unit 108 is a servo drive. The sample may be fixedly clamped into the second clamping chuck 106. A measurement unit 110 is adapted for measuring a physical parameter such as a torsion and/or a angle of torsion of the sample 102 in response to the application of the force at the first clamping chuck 104 and in response to the fixedly clamping into the second clamping chuck 106.

It is noted that the second clamping chuck 106 is free of a separate drive unit. In other words, the second clamping chuck 106 remains spatially fixed, apart from an impact of a load which may act on the second clamping chuck 106 in response to the application of the force to the first clamping chuck 104 by the drive unit 108. However, no separate drive unit is provided for the left hand portion of Fig. 1 so that a single drive unit 108 is sufficient to supply the entire apparatus 100 with mechanical forces.

A first mount 112 is provided which is fixed (for instance screwed) to a base plate 114 or support of the apparatus 100 in a fixed manner. Thus, the first mount 112 is spatially fixed, and, as can be taken from Fig. 1, the first clamping chuck 104 is mounted rigidly coupled to the first mount 112.

Beyond this, the apparatus 100 comprises a spatially moveable (see bidirectional arrow 116) second mount 118, so that a distance between the clamping chucks 104 and 106 in a horizontal direction in Fig. 1 can be adjusted by sliding the moveable mount 118 along the direction 116.

The apparatus 100 further comprises a variable test module 120 which can be substituted, and which is adapted in the present embodiment as a resonance adjustment module adapted for adjusting the apparatus 100 (particularly at least one operation mode thereof) so that it is operated in a resonance state.

Thus, Fig. 1 shows a variable test equipment concept for torsion analysis under static and cyclic, multiple stage torsion load or stress. The concept shown in Fig. 1 comprises the servo drive 108 which can be substituted by any other appropriate drive as well. The variable test module 120 can be substituted, for instance, by a gear for a proper transfer of a torsion moment in the context of static experiments. The clamping or chucking units 104, 106 which may also be denoted as sample fastening elements can also be configured in a mechanical mechanism, instead of a hydraulic configuration. The measurement unit 110 can be a torsion sensor and/or an angle of rotation pickup sensor. Reference numeral 118 may also denoted as a torsion momentum support, which is slidable (by a sliding cartridge member) in a longitudinal direction 116 and/or can be adjustable regarding angular properties or orientation properties along other axes than the sliding axis 116.

In the following, the apparatus 100 will be described in more detail.

Via the servo drive 108, it is possible to apply a static or a cyclic torsion momentum to the sample 102 which is supported on the torsion momentum support 118. This torsion momentum support 118 may be slidable in a longitudinal direction 116 and/or may be angularly elastic, in order to balance, if desired, length modifications at the sample 102 by cyclic loss of cohesion effects and by imperfections in the sample geometry. The variably employable module 120 allows the mounting of a gear for a transfer of the torsion momentum for static twisting experiments as well as the provision of a resonance module to operate the apparatus in a resonance state. Via a modification of a fly wheel mass, a first torsion eigenfrequency of the system 100 can be adjusted in order to enter a region of a test frequency relevant for the analysis of the dynamic strength/vibration resistance. The clamping system 104, 106 can be adapted, for instance, in a mechanical or in a hydraulic manner. At the measurement unit 110, it is possible to detect the torsion momentum as well as the twist angle at the sample 102.

In the following, advantages and differences of the apparatus 100 as compared to conventional approaches will be explained. Conventional apparatuses for performing torsion experiments in a resonance region only allow for a limited angular examination of a sample due to restrictions in the apparatus design. However, this limitation restricts the analyzable sample geometry. Conventional hydraulic torsion momentum analysis devices also have a limited elongation range, and may suffer from restrictions to small analysis frequencies of around 20 Hz, depending on the stiffness of the entire structure which is defined predominantly by the sample geometry. Based on the above recognitions, exemplary embodiments of the invention have been developed by the present inventor. Using drives such as a servo drive, there limitations regarding possible rotation angles are relaxed. This allows to perform static twist experiments for analyzing ductile materials which may require several rotations before breakage. Beyond this, vibration resistant experiments in the resonance region as well as without resonance are made possible. This may allow to investigate a possible influence of a frequency on the dynamic strength under torsion stress. Particularly, an operation of the apparatus at a first torsion eigenfrequency may allow for an analysis of the vibration resistance with low power consumption. According to exemplary embodiments of the invention, it is possible to measure the cyclic as well as the static deformation behaviour of the sample 102. Furthermore, by coupling energy supply systems of two or more apparatuses 100 constructed in the same or in a similar way, it is possible to lower the total energy consumption of the both apparatuses.

In the following, referring to Fig. 2, an apparatus 200 for analyzing a sample 102 according to another exemplary embodiment of the invention will be explained.

Fig. 2 shows a dynamic module configuration without resonance operation of the apparatus 200. In addition to the components shown in Fig. 1, the apparatus 200 shows a control cabinet 202 and has a protective housing 204. Linear guiding rails 206 are explicitly shown in detail as well. Reference numeral 112 may also be denoted as a drive bearing rack, and reference numeral 118 are also be denoted as a counter bearing rack.

Fig. 3 shows an apparatus 300 for analyzing a sample 102 according to a further exemplary embodiment of the invention.

The embodiment of Fig. 3 is a dynamic module operated with resonance. In addition to the components shown in Fig. 2, the apparatus 300 shown Fig. 3 further comprises a coupling 302 (or clutch) between the drive unit 108 and the first clamping chuck 104, which coupling 302 is stiff against torsion and is bending elastic. Moreover, an angular measurement system in a dynamic module configuration is shown and denoted with a reference numeral 304. Variable balance weights (inertia masses) are denoted with reference numeral 306. By adjusting the position and the weight of the masses, the apparatus 300 can be operated at a resonance frequency, i.e. close to the system's eigenfrequency.

A bearing rack of the dynamic module is denoted with reference numeral 308. Moreover, a hollow shaft 310 is provided at the clamping chuck 104.

In the following, referring to Fig. 4, an apparatus for analyzing a sample 102 according to another exemplary embodiment of the invention will be explained. The embodiment of Fig. 4 involves a static module. In addition to the components shown in Fig. 2 and Fig. 3, the apparatus 400 further comprises a harmonic drive gear 402, a bearing rack 404 of the static module, an angular measurement system 406 of the static module, and a static chuck 408 of the static module.

Fig. 5 shows a three-dimensional view 500 similar to the apparatus 300 shown in Fig. 3. Fig. 6 shows a detailed view 600 of a portion of Fig. 5.

Fig. 7 shows another detailed view of another portion of the apparatus of Fig. 5.

Fig. 8 shows a detailed three-dimensional view 800 of an apparatus according to an exemplary embodiment of the invention similar to the apparatus 200 shown in Fig. 2.

It should be noted that the term "comprising" does not exclude other elements or features and the "a" or "an" does not exclude a plurality. Also elements described in association with different embodiments may be combined.

It should also be noted that reference signs in the claims shall not be construed as limiting the scope of the claims.

Claims

C l a i m s

1. An apparatus for analyzing a sample, the apparatus comprising a first clamping chuck adapted for receiving a first portion of the sample; a second clamping chuck adapted for receiving a second portion of the sample; a drive unit adapted for applying a force to the first clamping chuck; a measurement unit adapted for measuring at least one physical parameter indicative of a property of the sample received by the first clamping chuck and the second clamping chuck in response to the application of the force to the first clamping chuck; wherein the second clamping chuck is free of a separate drive unit.

2. The apparatus of claim 1, wherein the drive unit comprises one of the group consisting of a servo drive, a combustion engine, a hydraulic drive, a synchronous machine, and an asynchronous machine.

3. The apparatus of claim 1 or 2, comprising in total exactly the one drive unit.

4. The apparatus of any one of claims 1 to 3, wherein the measurement unit is adapted for measuring the at least one physical parameter in a static manner, in a dynamic manner, or in a cyclic manner.

5. The apparatus of any one of claims 1 to 4, wherein the measurement unit is adapted for measuring at least one of the group consisting of torque, an angle of torsion, and a deformation behaviour.

6. The apparatus of any one of claims 1 to 5, wherein at least one of the group consisting of the first clamping chuck and the second clamping chuck comprises a mechanically actuable clamping chuck, and a hydraulically actuable clamping chuck.

7. The apparatus of any one of claims 1 to 6, wherein at least one of the group consisting of the first clamping chuck and the second clamping chuck is mounted on the apparatus in a substitutable manner.

8. The apparatus of any one of claims 1 to 7, comprising a set of first clamping chucks and/or a set of second clamping chucks differing regarding at least one property, each of the set of first clamping chucks and/or each of the set of second clamping chucks being mountable on the apparatus.

9. The apparatus of any one of claims 1 to 8, comprising a spatially fixed first mount on which the first clamping chuck is mounted, and comprising a spatially movable second mount on which the second clamping chuck is mounted.

10. The apparatus of any one of claims 1 to 9, comprising a resonance adjustment unit adapted for adjusting the apparatus to operate in a resonance state.

11. The apparatus of claim 10, wherein the resonance adjustment unit is adapted for adjusting an operation frequency of the apparatus to a resonance frequency.

12. The apparatus of claim 10 or 11, wherein the resonance adjustment unit enables an adjustment of a balance weight to bring the apparatus in the resonance state.

13. The apparatus of claim 12, wherein the balance weight is a radially shiftable mass.

14. The apparatus of any one of claims 1 to 13, comprising a geometry adjustment unit adapted for adjusting a geometry of the apparatus in response to a change of a geometric property, particularly in response to a thermally induced change of a length property.

15. The apparatus of any one of claims 1 to 14, comprising a harmonic drive arranged between the drive unit and the first clamping chuck.

16. The apparatus of any one of claims 1 to 15, comprising a coupling between the drive unit and the first clamping chuck, which coupling is stiff against torsion and bending elastic.

17. The apparatus of any one of claims 1 to 16, wherein the second clamping chuck is spatially fixed.

18. A method of analyzing a sample, the method comprising receiving a first portion of the sample by a first clamping chuck; receiving a second portion of the sample by a second clamping chuck; applying a force to the first clamping chuck by a drive unit; measuring at least one physical parameter indicative of a property of the sample received by the first clamping chuck and the second clamping chuck in response to the application of the force to the first clamping chuck; wherein the second clamping chuck is free of a separate drive unit.