Patent Application
20200066184
The disclosure of the present patent application relates to educational tools and methods, and particularly to a system and method for teaching the principles of mechanical failure.
In engineering, structural or mechanical failure refers to the loss of structural integrity, or the loss of load-carrying capacity, in either a structural component, or the structure itself. Structural failure is initiated when a material is stressed beyond its strength limit, causing fracture or excessive deformations. One limit state that must be accounted for in structural design is ultimate failure strength.
To construct an item with structural integrity, an engineer must first consider a material's mechanical properties, such as toughness, strength, weight, hardness and elasticity, and then determine the size and shape necessary for the material to withstand the desired load for a long life. Since members can neither break nor bend excessively, they must be both stiff and tough. A very stiff material may resist bending, but unless it is sufficiently tough, it may have to be very large to support a load without breaking. On the other hand, a highly elastic material will bend under a load even if its high toughness prevents fracture.
Structural failure can occur from many types of problems, most of which are unique to different industries and structural types. However, most can be traced to one of four main causes: The first cause is that the structure is not strong and tough enough to support the load, due to either its size, shape, or choice of material. If the structure or component is not strong enough, catastrophic failure can occur when the structure is stressed beyond its critical stress level. The second type of failure is from fatigue or corrosion, caused by instability in the structure's geometry, design or material properties. These failures usually begin when cracks form at stress points, such as squared corners or bolt holes too close to the material's edge. These cracks grow as the material is repeatedly stressed and unloaded (cyclic loading), eventually reaching a critical length and causing the structure to suddenly fail under normal loading conditions.
The third type of failure is caused by manufacturing errors, including improper selection of materials, incorrect sizing, improper heat treating, failing to adhere to the design, or shoddy workmanship. This type of failure can occur at any time and is usually unpredictable. The fourth type of failure is from the use of defective materials. This type of failure is also unpredictable, since the material may have been improperly manufactured or damaged from prior use.
In order to teach and study mechanical failure, destructive testing is typically used; i.e., a sample material is selected and appropriate forces are applied until the sample experiences actual failure. Given that actual failure is induced in the material being tested, the sample itself is effectively destroyed. Although effective, this obviously can be problematic in an educational setting, in that the necessary equipment to induce and measure the failure forces can be extremely complicated, expensive and potentially dangerous. Further, following each test, a new sample must be obtained and prepared. Thus, an educational system and method for teaching mechanical failure solving the aforementioned problems is desired.
The educational system for teaching mechanical failure includes first and second specimen pieces. The first and second specimen pieces are adapted to be magnetically joined to one another at a selected magnitude of magnetic force. A linear force measuring device, such as a load cell, for example, is secured to the first specimen piece and a support frame. A linear actuator is secured to the support frame and the second specimen piece to selectively apply a separation force to the first and second specimen pieces. In use, a user may increase a magnitude of the separation force until the first and second specimen pieces separate from one another. The measured separation force when the first and second specimen pieces separate from one another is educationally representative of a required real world force to cause mechanical failure, and this measured value may be compared against the input modeled force.
These and other features of the present disclosure will become readily apparent upon further review of the following specification and drawings.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
Now referring to
In
It should be understood that controller 100 may be any suitable computer system, controller or the like, such as that diagrammatically shown in
Processor 114 may be associated with, or incorporated into, any suitable type of computing device, for example, a personal computer or a programmable logic controller. The display 118, the processor 114, the memory 112 and any associated computer readable recording media are in communication with one another by any suitable type of data bus, as is well known in the art.
Examples of computer-readable recording media include non-transitory storage media, a magnetic recording apparatus, an optical disk, a magneto-optical disk, and/or a semiconductor memory (for example, RAM, ROM, etc.). Examples of magnetic recording apparatus that may be used in addition to memory 112, or in place of memory 112, include a hard disk device (HDD), a flexible disk (FD), and a magnetic tape (MT). Examples of the optical disk include a DVD (Digital Versatile Disc), a DVD-RAM, a CD-ROM (Compact Disc-Read Only Memory), and a CD-R (Recordable)/RW. It should be understood that non-transitory computer-readable storage media include all computer-readable media, with the sole exception being a transitory, propagating signal.
Returning to
A linear actuator 24 is secured to the support frame 12 and the second specimen piece 22 to selectively apply a separation force to the first and second specimen pieces 20, 22. It should be understood that any suitable type of linear actuator may be used. It should be understood that connector 30 is shown for exemplary purposes only. In
In use, a student may increase a magnitude of the separation force until the first and second specimen pieces 20, 22 separate from one another. As shown in
As noted above, the load cell 16 measures, in real time, the applied force during the test. Load cell 16 is connected to controller 100, and the data may be stored in memory 112 for further analysis and validation. A graph demonstrating the relationship between the applied force with respect to time may be presented to the student on display 118 of controller 100. Additionally, as noted above, whereas load cell 16 transmits the measured force reading to controller 100, the additional digital force meter 18 may display an instant local digital force reading. In addition to being illustrative to the student, this measurement can be provided for purposes of safety. In the case of controller malfunction or error, the user can still stop the system in an emergency situation based on the measured instant force reading.
Further, as shown in
It is to be understood that the educational system and method for teaching mechanical failure is not limited to the specific embodiments described above, but encompasses any and all embodiments within the scope of the generic language of the following claims enabled by the embodiments described herein, or otherwise shown in the drawings or described above in terms sufficient to enable one of ordinary skill in the art to make and use the claimed subject matter.
