Patent Application
20120151717
Certain embodiments disclosed herein relate generally to fabrication of structural beams. More specifically, certain embodiment disclosed herein related generally to securing together the components of structural beams.
Structural beams come in a wide variety of forms. The form of a structural beam may be determined by a set of variables that may comprise the geometry of the beam and the material of the beam.
One method of fabrication of structural beams comprises welding together two or more components of structural beams. In some embodiments, the components of the structural beam may comprise a web and a flange. In some embodiments, the web and the flange may be joined together by a joining operation to form a beam.
Many materials undergo dimensional change in response to temperature change. Dimensional change in response to temperature change may also be known as thermal strain. Without limitation, some materials expand when heated and contract when cooled.
A joining operation may comprise heating of one or more components to be joined. In some joining processes, the component may have its temperatures changed dramatically from the temperature to which the component will be subjected to during normal use. In some joining processes one component or one part of the component may be heated or have its temperature changed unevenly with respect to other parts of the same component or other components. Uneven heating can result in uneven thermal strain or thermal distortion.
In some operations, uneven thermal strain of a component may result in unacceptable product quality, or may result in additional undesirable manufacturing cost or time. In some joining operations thermal strain of a component during or after joining operations may not be negligible and may result in unacceptable product quality, or may result in additional undesirable manufacturing cost or time. In some operations, uneven thermal strain or thermal distortion may result in unacceptable bending or warpage of the finished beam.
It remains desirable to provide methods of securing the components of beams so that uneven strain or distortion of the beam during or after joining operations, does not result in unacceptable product quality and does not result undesirable additional manufacturing cost or time.
Provided is an apparatus comprising a tensioner, a first clamp, a first slide, a second clamp, and a second slide. A tensioner may be adapted to apply a tensile force along a first dimension. A first clamp may comprise a first end and a second end with at least one of the ends movable with respect to the other. A first clamp may be adapted to apply a clamping force between the first end and the second end. A first slide may be adapted to secure the first clamp such that the first clamp may be substantially free to move in a second dimension. A second clamp may comprise a first end and a second end with at least one of the ends movable with respect to the other. A second clamp may be adapted to apply a clamping force between the first end and the second end. A second slide may be adapted to secure the second clamp, such that the second clamp may be substantially free to move in the second dimension.
Further provided is an apparatus that may comprise a tensioner, a first clamp, a first slide, a second clamp, and a second slide. A tensioner may be adapted to apply a tensile force along a first dimension to an associated first beam component. A first clamp may be adapted to compressively engage an associated second beam component with the associated first beam component. A first slide may be adapted to secure the first clamp, such that the first clamp may be substantially free to move in a second dimension. A second clamp may be adapted to compressively engage the associated second beam component with the associated first beam component. A second slide may adapted to secure the second clamp, such that the second clamp may be substantially free to move in the second dimension.
Further provided is a method comprising applying a tensile force along a first dimension to a first beam component, applying a compressive force with a first clamp to compressively engage at least part of a second beam component with at least part of the first beam component, and applying a compressive force with a second clamp to compressively engage at least part of the second beam component with at least part of the first beam component. The first clamp may be to move in a second dimension. The first compressive force may be applied in a direction substantially parallel to the second dimension. The second clamp may be free to move in a second dimension. The second compressive force may be applied in a direction substantially parallel to the second dimension.
Reference will be made to the drawings,
As noted above, the form of a structural beam depends, at least in part, on the geometry of the beam and the material of the beam. In some embodiments, a beam may be comprised of multiple beam components joined to form the beam. A beam component may comprise a web or a flange.
Structural beams may comprise I-beams, T-beams, angles, channels, hollow structural sections, and other geometries. The geometry of a beam may also be defined by parameters that may comprise, the length of the beam, the height of the beam, the weight of the beam per unit length, flange width, web thickness, flange thickness, cross-sectional area, and cross-sectional moment of inertia.
Structural beams come in a wide variety of materials. Structural beams may comprise structural materials. Structural materials may comprise steel, stainless steel, iron, iron alloys, aluminum, aluminum alloys, titanium, titanium alloys, nickel, nickel alloys, other metals or metal alloys, composite materials, polymers, wood, concrete, and other materials. Steel may comprise, carbon steels, high strength low alloy steels, corrosion resistant high strength low alloy steels, and quenched and tempered alloy steels.
A structural beam may be formed from multiple beam components. A beam component may be in the form of a plate, a strap, a rod, or another form. In some embodiments, the beam components may comprise a first beam component and a second beam component, where the first beam component comprises a web and the second beam component comprises a flange. In some embodiments the beam components may be elongated beam components. In some embodiments, the beam components may comprise a first beam component and a second beam component, where the first beam component may comprise an elongated web and the second beam component may comprise an elongated flange. A beam component of a beam may comprise any of the above listed structural materials.
Without limitation,
The beam components 120, 140 may be joined to form the structural beam 100. In certain embodiments, such as, without limitation, that shown in
In certain embodiments, and without limitation, a plurality of beam components 120, 140 may be held substantially fixed with respect to one another during a process used to join the beam components 120, 140 into the structural beam 100. In certain embodiments and without limitation, sections of beam components 120, 140 may be held substantially fixed with respect to one another during the process used to join the beam components 120, 140 into the structural beam 100. As shown in
In certain embodiments, and without limitation, a fixture 200 may comprise a tensioner 210, a clamp 220, a slide 370, a location surface 230, or a float system 260.
A tensioner 210 may be any device adapted to apply a tensile force to a beam component 120, 140. In certain embodiments, a tensioner 210 may comprise hydraulic machinery 400, pneumatic machinery, a mechanism or some combination thereof. Hydraulic machinery 400 may comprise a hydraulic cylinder 410, a hydraulic pump, a valve, an actuator, a reservoir, an accumulator, hydraulic fluid, or some combination thereof. Pneumatic machinery may comprise a pneumatic cylinder, a compressor or other pressurized gas source, a valve, an reservoir, bottle, or other gas storage device, a gas, or some combination thereof. A mechanism may comprise, an input link, an output link, an connector link, a linkage, a lever, a pivot, a fulcrum, an axle, a screw, a spring, or some combination thereof.
A tensioner 210 may comprise an adaptation for engagement with a beam component 120, 140. An adaptation for engagement with a beam component 120, 140 may comprise a clamp, a mechanical fastener, a hole adapted to engage a mechanical fastener, or some combination thereof. In some embodiments, and without limitation, as shown in
In certain embodiments, a tensioner 210 may be adapted to induce substantial strain in a beam component 120, 140. Some beam components 120, 140 may comprise components having a large cross-section, having a high modulus of elasticity, or some combination thereof. In certain embodiments, tensioner 210 may be adapted to induce substantial strain in components having a large cross-section, having a high modulus of elasticity, or some combination thereof. In certain embodiments, tensioner 210 may be adapted to provide forces on the order of multiple millions of Newtons.
A beam component 120, 140 may have a neutral axis. In certain embodiments, the beam component 120, prior to being joined with another component 140 to form the beam 100, may have a free state in which the beam component 120 has a substantially straight neutral axis. As noted above, tensioner 210 may apply a tensile force to the beam component 120. A tensile force, like all forces, may be described by a vector having both magnitude and direction. The direction of application of a tensile force applied to the beam component 120 may be parallel to the neutral axis of the beam component 120, at an angle to the neutral axis of the beam component 120, or skew to the neutral axis of the beam component 120. Without limitation, the direction of application of a tensile force applied to beam component 120 may be parallel to the neutral axis of the beam component 120 and offset from the plane comprising the neutral axis so that application of the tensile force to the beam component 120 induces a force in the beam component 120, and also induces a moment in the beam component 120. As shown in
In certain embodiments and without limitation, a section of first beam component 120 may be held substantially fixed with respect to a section of second beam component 140 in one or more dimensions by a fixture 200, by exerting a compressive force on the section of first beam component 120 and on the section of second beam component 140 using a clamp 220. In certain embodiments and without limitation, the clamp 220 may comprise a first end 310 and a second end 320 wherein the first end 310 and the second end 320 may be adapted to apply a compressive force therebetween. In certain embodiments, the clamp 220 may comprise an actuator. An actuator may comprise hydraulic machinery 330, pneumatic machinery, a mechanism, or some combination thereof, adapted to induce a compressive force between the first end 310 and the second end 320. As shown in
In certain embodiments, a clamp 220 may comprise an actuator having a maximum actuation distance. A maximum actuation distance is the maximum displacement over which actuator is capable of acting. Without limitation, in certain embodiments, as shown in
Clamping distance is the distance between the first end 310 and the second end 320. In certain embodiments, the clamp 220 may comprise a clamping distance that is greater than the maximum actuation distance of the actuator. In certain embodiments, the clamp 220 may comprise an adjustable connection 340 that permits the clamping distance between the first end 310 and the second end 320 to be adjusted. Without limitation, the clamping distance may permit the clamp 220 to accept and clamp together components 120 and 140 that may be taller, wider, or otherwise larger than the maximum actuation distance of the actuator. As shown in
In certain embodiments, the clamp 220 may comprise a fastener 360 adapted to hold the component 140 in a fixed position, in one or more dimensions, with respect to at least part of clamp 220. Without limitation, in certain embodiments, the clamp 220 may comprise a fastener 360 adapted to hold the component 140 in a fixed position with respect to the second end 320. In certain embodiments, and without limitation, as shown in
In certain embodiments, the clamp 220 may be engaged with a tensioner 210, another clamp 220, a location surface 230, other portions of a fixture 200, or the ground. In certain embodiments, the clamp 220 may be engaged with a tensioner 210, another clamp 220, a location surface 230, other portions of a fixture 200, or the ground in a manner that permits the clamp to move in one or more dimensions. In certain embodiments, the clamp 220 may be engaged to a tensioner 210, another clamp 220, a location surface 230, other portions of a fixture 200, or the ground with a slide 370.
A slide 370 may comprise a rail, shaft 370, track, mechanism, or other guide that permits the clamp 220 to move in one or more dimensions. In certain embodiments, and without limitation, the slide 370 may be straight or curved. In certain embodiments, and without limitation, as shown in
Without limitation, in certain embodiments, permitting the clamp 220 to move may allow component 120, 140 or a section of component 120, 140 to move or to be strained while still maintaining engagement with another component 120, 140 clamped thereto. Without limitation, in certain embodiments, permitting the clamp to move can allow component 120 or a section of component 120 to move or be strained, such as, without limitation, by inducing a moment in beam component 120 that bends the beam component 120 downwards at the middle thereof, while still maintaining engagement with another component 140 clamped thereto.
In certain embodiments, the clamp 220 may be engaged with a float system 260. A float system is a system adapted to minimize or eliminate the effects of the weight of the clamp 220 on the clamp 220, on beam components 120, 140, on the beam 100, or on some combination thereof with which the clamp 220 may be engaged. The weight of clamp 220 may act in the vertical downward direction. In certain applications, and without limitation, the weight of the clamp 220 acting on beam component 120, 140 or in the resulting beam 100, may create distortion in the beam component 120, 140 or in the resulting beam 100. In certain applications, and without limitation, the float system 260 may be engaged with the clamp 220 in order to minimize or eliminate the effects of the weight of the clamp 220 in beam component 120, 140 or in the resulting beam 100. The float system 260 may comprise a system adapted to apply forces to the clamp 220 substantially opposite in magnitude and direction to those forces of the weight of the clamp 220. The float system 260 may comprise a counter-weight engaged to the clamp via a pulley system. In certain embodiments, the force acting on the clamp 220 from the float system 260 may be substantially equal to the weight of the clamp 220 and may be substantially opposite in direction to the direction of the force of the weight of the clamp 220. In certain embodiments, the force acting on the clamp 220 from the float system 260 may be substantially equal to the product of the weight of the clamp 220 and the sine of the angle of the direction of application of the force acting on the clamp 220 with respect to the ground. In certain embodiments, and without limitation, as shown in
A clamp 220 may engage objects located therebetween with an engagement surface 910. As shown in the
In certain embodiments, a secondary clamp may comprise a first end 362 and second end 364, wherein one or more of first end 362 and second end 364, may comprise an engagement surface 910. As noted above, an engagement surface 910 may comprise an engagement shoe 920 or an engagement roller 930. In certain embodiments, and without limitation, as shown in
A location surface 230 may be any surface adapted to provide a stop, jam, or other surface, plane, line, or point against which beam component 120, 140 may be placed in order to locate the beam component 120, 140. The location surface 230 may be defined by a plate, a strap, a block, a rod, a shaft, a rail, a beam, or any other object.
In certain embodiments, and without limitation, as shown in
Some joining operations heat or cool beam components 120, 140 during the joining operations. Many materials of which beam components may be formed undergo dimensional changes when heated or cooled. Some joining operations cause beam components subject thereto to undergo dimensional changes or thermal strain. The thermal strain per unit of temperature change of a material during temperature change may be quantified by a coefficient of linear thermal expansion. Without limitation, in many embodiments, the components of the beam 100 expand when heated.
As noted above, welding may be a joining operation. Welding of a component that expands when heated may result in expansion of the component to be joined during the welding process. In some embodiments, and without limitation, with beam components 120, 140 of known geometry and comprising a known material to be joined into beam 100 using a known joining process, it may be possible to make reliable engineering predictions about the behaviors of the beam components 120, 140 during and after the joining operation with respect to dimensional changes or thermal strains to which they may be subject such that compensating measures may be taken with respect to the predicted dimensional changes or thermal strains.
For sake of example, and without limitation, an elongated first beam component 120 and an elongated second beam component 140 may each comprise a steel of known mechanical properties and known geometries. For sake of illustration, and without limitation, for the steel comprising the beam components 120, 140, the coefficient of linear thermal expansion may be approximately, 12×10̂-6 cm/cm per degree C. A 30 foot elongated beam 100 may be formed by welding together a 30 foot elongated first beam component 120 and a 30 foot elongated second beam component 140 with an elongated weld of known properties. For sake of illustration, and without limitation, the welding operation may heat knowable regions of the component to temperatures approximately 1300 degrees C. above the temperatures to which the component will be subjected to during normal use. For sake of illustration, and without limitation, a simple approximation of the dimensional change of beam component 140 in the dimension of elongation during welding may be made by taking the product of the coefficient of linear thermal expansion of the steel of the beam, 12×10̂-6 cm/cm per degree C., the approximate change in temperature, 1300 C, and the total length of the beam component, 30 feet, the thermal strain would be approximately 0.0156 cm/cm, yielding a dimensional change of 0.468 feet or approximately 5.6 inches. Similarly, the dimensional change of beam component 140 in the dimension of elongation subsequent to welding would be a reduction of the thermal strain of approximately 0.0156 cm/cm and a reduction of 0.468 feet over that of it's length during welding. This expected post-welding reduction may, in some situations, result in uneven strain or distortion of the beam unless measures are taken to compensate for this expected post-welding reduction of the thermal strain and reduction of length.
In certain embodiments, means to compensate for post-welding reduction of the thermal strain and reduction of length in one component may comprise preparation of another component to be over-sized in some way. In some embodiments, and without limitation, web 120 may be prepared to be over-sized prior to joining with flange 140. In some embodiments, and without limitation, the web 120 may be prepared to be over-sized prior to joining with the flange 140 such that web 120 forms a curved component with a first edge of web 120 being substantially longer than a second edge of web 120. In some embodiments, and without limitation, the over-sized web 120 may be joined with the flange 140 with a welding operation that causes flange 140 to warm to a temperature substantially above the nominal operating temperature of the beam 100 and to expand as a result of thermal strain. Subsequent to the joining operation, the flange 140 of beam 100 may cool and contract as a result. The contracting flange 140 may exert a compressive stress on the web 120 and the web 120 may exert tensile stress on the contracting flange 140. Careful selection of the geometry, or the material, or both the geometry and the material of the flange 140, or the web 120, or both the flange 140 and the web 120, may result in beam 100 that has the desired dimensions after the beam 100 and the flange 140 and web 120 cool to the nominal operating temperature of the beam 100.
In certain embodiments, means to compensate for expected post-welding thermal contraction may comprise adding strain to first components 120 or a section of first component 120 such that the total strain in the first component 120 may be substantially equal to the thermal strain in the component 140 to which the first component 120 is to be joined. Total strain in any direction in any region of any component may be a combination of thermal strain and applied mechanical strain. In some embodiments, and without limitation, a desired amount of applied mechanical strain may be applied using the tensioner 210 to induce a desired mechanical strain in a section of beam component 120. In certain embodiments and without limitation, a tensioner 210 may be used to induce the desired mechanical strain in a section of beam component 120 by applying a force parallel to the neutral plane of the beam component and offset from the plane comprising the neutral axis. The mechanical strain induced by the tensile force may be calculated as shown in Equation A below:
Wherein:
For example, and without limitation, it may be possible to induce a mechanical strain equal to 0.0156 cm/cm in the bottom edge of the beam component 120 shown in
In certain embodiments in which strain is added to components or regions of components such that the total strain therein may be substantially equal to the thermal strain of components to which they may be joined, the fixture 200 may be used to secure or hold the beam components 120, 140. The fixture 200 may comprise the tensioner 210 adapted to apply a desired amount of force to induce a desired mechanical strain in a section of beam component 120. In certain embodiments and without limitation, the tensioner 210 may be used to induce a desired mechanical strain in a section of beam component 120 by applying a force that also induces a moment within the beam component 120, causing the beam component 120 to bend. The fixture 200 may comprise the clamp 220 adapted to apply a compressive force to hold a section of first beam component 120 and a section of second beam component 140 substantially fixed with respect to one another in one or more dimensions while still permitting the clamped beam components 120, 140 to move in at least one dimension. In certain embodiments, the clamp 220 may be adapted to permit the clamped beam components 120, 140 to bend in response to the moment induced by the tensioner 210 while still holding the section of first beam component 120 and the section of second beam component 140 substantially fixed with respect to one another.
While the method and apparatus for manufacturing a beam has been described above in connection with the certain embodiments, it is to be understood that other embodiments may be used or modifications and additions may be made to the described embodiments for performing the same function of the method and apparatus for manufacturing a beam without deviating therefrom. Further, the method and apparatus for manufacturing a beam may include embodiments disclosed but not described in exacting detail. Further, all embodiments disclosed are not necessarily in the alternative, as various embodiments may be combined to provide the desired characteristics. Variations can be made by one having ordinary skill in the art without departing from the spirit and scope of the method and apparatus for manufacturing a beam. Therefore, the method and apparatus for manufacturing a beam should not be limited to any single embodiment, but rather construed in breadth and scope in accordance with the recitation of the attached claims.
| Number | Date | Country | |
|---|---|---|---|
| 61423358 | Dec 2010 | US |
