The fatigue life of SMA wires is also strongly influenced by the stress and strain reached in their actuated state, as suggested in [ ], where SmartFlex NiTi wires subjected to cyclic tensile loads were experimentally investigated. To reduce the thermal and mechanical overstresses induced in actuated SMAs, bi-stable configurations were investigated [ , , , , ] to develop mechanisms able to shift between a stable de-actuated configuration and a stable actuated configuration.
Hence, the activation of the SMA is needed to actuate and de-actuate the devices, resulting in energy-free actuation states where an electric current is not needed to keep the device in its actuated configuration, reducing the power consumption and the thermal and mechanical overstresses as well. Moreover, in [ ] considerations related to the low energy efficiency of SMA actuators ware addressed.
Different load cases for SMA actuators were compared, resulting in an efficiency that ranges between 0. Adaptive aerodynamics is one of the most promising fields of applications for shape memory alloy components, thanks to their morphing capabilities. To date, several solutions have been investigated to modify the aerodynamic field in aeronautical applications. Shape Memory Polymers SMP were used to modify the wing chord, to tailor the wing to specific scenarios. The adoption of actively cooled SMA for the deployment of flexible control surfaces was investigated in [ 48 ], while in [ 96 ] SMA wires were used to modify the camber of a morphing wing.
Experimental and numerical investigations on a morphing airfoil were carried out in [ 58 ], where SMA springs were used to actuate discrete points of the structure to achieve the desired deformation. In [ ], SMP hinges, adopted to modify the sweep angle of a wing, were numerically and experimentally investigated, while in [ ] the thickness of a flexible skin morphing wing is controlled by means of SMA actuators. A feasibility study of wing flap actuation based on shape memory alloys is presented in [ ]. A wing composed of different telescopic segment deployed by means of SMA actuators is presented in [ 29 ] to improve the aerodynamic performances while reducing the wing volume stowage.
In [ , ], SMAs were used to design and manufacture smart vortex generators, and their performance was investigated by means of experimental wind tunnel tests. In [ 38 ], an application to deploy and stow a flap edge fence is presented. Figure 1 summarizes the present and future applications of SMA concepts for adaptive airplanes aerodynamics. The solutions developed for adaptive aerodynamics can be easily transferred from the aeronautical to the automotive field.
In this work, two preliminary case studies, finalized to the adaptive aerodynamic, are briefly introduced. The presented case studies aim to demonstrate feasibility and inspire future applications to develop SMA-based devices in the adaptive aerodynamics field. Hence, in this preliminary design stage, the SMA characteristics have not been taken into account; instead we focus on the load exerted during the actuation. Indeed, in an advanced design stage, more detailed analyses must be performed, supported by experimental data.
In the proposed case studies, SMA actuators have been adopted to modify the aerodynamic field of vehicle on demand. The presented case studies are focused on the spoiler and on the rear upper panel components. The aim of Case study 1 is to demonstrate the feasibility of SMA-based actuation of a spoiler trailing edge under service aerodynamic loads.
Spoiler and actuated elevator: a cross section; b isometric view unit: mm. The trailing edge actuation will result in a variation in drag and downforce. From preliminary aerodynamic studies, a requirement of at least 10 mm trailing edge displacement should be achieved to guarantee a significant variation of the aerodynamic field. The aim of the second case study see Figure 4 is to demonstrate the feasibility of the actuation of rear upper panels of a vehicle, inducing a variation of the aerodynamic field, with consequent variation of drag and downforce to improve the vehicle performance under service aerodynamic loads.
In order to perform realistic numerical computations, the geometry configuration of an existing sports car has been taken into account. From preliminary aerodynamic studies, a 10 mm displacement of the rear upper panel has been considered sufficient to significantly modify the aerodynamic field. The Shape Memory Alloys are metallic alloys able to recover an initial prescribed shape when subjected to temperature variation.
In particular, an increase of temperature beyond a prescribed threshold generates a phase transition from a martensitic crystal structure to a stable austenitic crystalline structure, as shown in Figure 5. Since the phase transition induces a rearrangement of the microstructural arrays, the SMA mechanical properties including the elastic modulus and the yield strength are significantly modified [ , , , ]. In this phase, a mm long wire, characterized by a 1 mm diameter circular profile representative of a bundle of SMA wires, is considered.
Table 1 reports the mechanical properties of the SMA material system. Ni 52 Ti 48 mechanical properties [ ]. A simplified SMA material model has been adopted. This approach, although not accounting for all the characteristics of the SMA such as the hysteresis, can still be used in a preliminary study to evaluate the load resulting from the SMA actuation. However, in a more advanced design stage, detailed SMA constitutive models [ , , , , ] must be used to assess the behavior of the SMA actuators. In this work, the experimental data found in [ , ] have been used.
In particular, the elastic moduli and the coefficients of thermal expansion needed to describe the behavior of the alloy were derived from a database of experimental tests, exploiting the calibration proposed in [ ]. In particular, the elastic moduli E was experimentally measured from isothermal tensile tests: for each desired temperature, the SMA wires were subjected to a tensile load at a constant temperature.
Hence, the CTE at different temperatures can be expressed as a function of the measured strains and temperatures. In order to numerically replicate the SMA characterization procedure, as a preliminary step to the case studies analyses, a NiTiNOL wire has been clamped at its extremities. This analysis is aimed at the validation of the proposed simplified material model with respect to the literature data.
Indeed, it does not describe the behavior of the SMA wire used as an actuator, due to the different boundary conditions.
The results of the ABAQUS numerical test, in terms of stress as a function of the temperature, have been found to be in agreement with the data reported in [ ], as shown in Figure 6 , where the numerical test results are compared to the reference ones. Thus, the validated material model has been used in the following test cases, tailoring the number of SMA wires according to the specific application. Numerical test results [ ]. According to the proposed finite element discretization, two solid models Figure 7 a,b have been considered.
The first model represents the fixed part of the spoiler, while the second represents the moving tip see Figure 7. The two solid models have been discretized by means of four-noded shell elements with a reduced integration scheme S4R. In Figure 7 , details of both solid models with corresponding numerical discretization are shown, while the mechanical properties of the adopted aluminum alloy have been reported in Table 3. Case study 1 details : a , b geometries; c FEM.
A hinge placed between the fixed and the moving part allows the rotation of the tip. As already mentioned, two mm-long SMA wires have been introduced to connect the fixed part to the moving tip, through two holes drilled on the fixed part see Figure 7 a. The position of the SMA wires has been chosen to maximize the moment with respect to the hinge. The section of the wires and the properties of the material are defined in agreement with the preliminary study on SMA materials.
In order to guarantee the return of the device to its initial position at SMA deactivation, two elastic beams have been placed between the fixed and moving tip opposed to the SMA wires. Details of the SMAs and beams locations are reported in Figure 8. Two different analyses have been considered.
The first analysis has been finalized to the testing of the SMA wire mechanical behavior and the latter has been finalized to the investigation of the influence of the external aerodynamic load and the elastic load of the beams on the SMA mechanical behavior and on the SMA actuation. Indeed, an equivalent aerodynamic load of 2. Since the weight is one order of magnitude lower than the aerodynamic load, it has been neglected. In Table 4 , the results of both configurations are reported, while Figure 9 shows Case study 1 in actuation mode with the application of both the aerodynamic load and the elastic load from the beams.
According to the numerical results, the investigated device can satisfy the displacement requirement 10 mm. Case study 2 is focused on the actuation of the rear upper panel of a bonnet, by means of properly located mm-long NiTiNOL wires, aimed to increase the drag and the downforce.
The numerical model has been realized by means of eight-noded 3D solid elements with a reduced integration scheme C3D8R. A hinge has been placed between the fixed part of the bonnet and the rear upper panel interfaces to allow its rotation. The rear upper panel can recover its initial position by means of a torsion spring placed in the hinge. As in the previous case study, the weight has been neglected since it is one order of magnitude below the aerodynamic load.
In Figure 10 , the numerical model, including the location of the SMA wires and of the torsion spring, is reported.
Rear upper panel actuation, details of the numerical model, and locations of SMA and torsion spring. Finally, in Figure 11 , the structure in actuation mode is reported. Again, for this configuration, the requirement on displacements 10 mm needed to obtain a significant aerodynamic field variation has been satisfied. However, it is worth noting that modifications to the number and the length of the SMA wire can help to tailor actuation displacements.
Engineering Aspects of Shape Memory Alloys
An overview of SMA-based smart structures has been presented in this work. Extensive studies, analytical, numerical, and experimental, have been found in the literature dealing with shape memory alloys, which can be considered suitable for adaptive aerodynamic applications, thanks to their morphing capabilities. Indeed, the research efforts on SMA-based actuators have been focused on the development of devices able to induce axial, bending, or twisting deformations. Moreover, the adoption of shape memory alloys results in simpler and lighter devices compared to the conventional actuators, significantly reducing the weight and the cost of the components.
Thus, the interest in shape memory alloy applications is increasing even more, as demonstrated by the number of articles published and patents issued, as reported in Figure Articles published and U. Sources: Scopus and Uspto. As a matter of fact, the majority of the applications presented in the literature are confined to the aerospace field, where performance requirements are demanding, as shown in detail in Figure 13 , where the number of articles clearly belonging to the aeronautical or automotive fields are compared.
Articles published in the aeronautical and automotive fields. Sources: Scopus. Hence, based on this literature research, a feasibility study of the development of SMA-based smart actuators for automotive applications, mostly derived from the aerospace experience, has been presented in this paper. In order to focus on the feasibility rather than on the executive design of SMA concepts, in this work a simplified model, descriptive of the NiTiNOL characteristics, has been employed.
Moreover, with the same objective in mind, preliminary, if realistic, aerodynamics loads have been considered for the proposed SMA concepts. Two case studies have been presented: the trailing edge actuation of a spoiler very close to the aerospace background and the rear upper panel deformation of a vehicle. The provided numerical analyses have demonstrated the feasibility of the presented SMA-based smart devices. As a general remark, the key design parameters to be considered in SMA applications, such as the maximum attained force and displacement and the operating range temperature, can be controlled by varying the material, size, and shape of the adopted SMA wires.
Hence, the presented solutions can be improved by tailoring the SMA geometry and material characteristics. National Center for Biotechnology Information , U. Journal List Materials Basel v. Materials Basel. Published online Feb Author information Article notes Copyright and License information Disclaimer. Received Jan 29; Accepted Feb Abstract The development of structures able to autonomously change their characteristics in response to an external simulation is considered a promising research field.
Keywords: shape memory alloy, smart structure, preliminary design. Introduction The continuously increasing requirements of structures capable of autonomously adapting their shape according to specific varying conditions has led to an increase, in the last few decades, of research studies on morphing technologies. Overview of the State of the Art of SMA Actuators Several investigations on morphing concepts, focusing on morphing components, can be found in the literature [ 46 , 47 , 48 , 49 , 50 , 51 ].
Adaptive Aerodynamic Applications Adaptive aerodynamics is one of the most promising fields of applications for shape memory alloy components, thanks to their morphing capabilities. Open in a separate window. Figure 1. Locations of adaptive aerodynamic applications in the aeronautical field. Figure 2. Locations of adaptive aerodynamic applications in the automotive field. Description of Case Studies 4. Case Study 1—Trailing Edge Actuation The aim of Case study 1 is to demonstrate the feasibility of SMA-based actuation of a spoiler trailing edge under service aerodynamic loads. Figure 3. Case Study 2—Rear Upper Panel Actuation The aim of the second case study see Figure 4 is to demonstrate the feasibility of the actuation of rear upper panels of a vehicle, inducing a variation of the aerodynamic field, with consequent variation of drag and downforce to improve the vehicle performance under service aerodynamic loads.
Figure 4. Numerical Simulation 5. SMA Modeling The Shape Memory Alloys are metallic alloys able to recover an initial prescribed shape when subjected to temperature variation. Figure 5. Table 1 Ni 52 Ti 48 mechanical properties [ ]. Table 2 SMA temperature-dependent mechanical and thermal properties. Figure 6. Figure 7. Table 3 AlT6 mechanical properties. Figure 8. Trailing edge actuation, details of the SMA, hinge, and beam locations. Figure 9. Table 4 Results of Case study 1. Boundary Conditions Max Displacement mm Without load and beam Case Study 2 Case study 2 is focused on the actuation of the rear upper panel of a bonnet, by means of properly located mm-long NiTiNOL wires, aimed to increase the drag and the downforce.
Figure Funding This research received no external funding. Conflicts of Interest The authors declare no conflict of interest. References 1. Qiu J. Smart skin and actuators for morphing structures. Weisshaar T. Induced drag reduction using aeroelastic tailoring with adaptive control surfaces. Bowman J.
Hwang S. Piezoresistive behavior and multi-directional strain sensing ability of carbon nanotube-graphene nanoplatelet hybrid sheets. Smart Mater. John A. Synthesis and characterization of cellulose acetateecalcium carbonate hybrid nanocomposite. Part B Eng.
Hou Y. Graded conventionalauxetic Kirigami sandwich structures: Flatwise compression and edgewise loading. Wang W. Smart soft composite actuator with shape retention capability using embedded fusible alloy structures. Brinson L. One-dimensional constitutive behavior of shape memory alloys: Thermomechanical derivation with non-constant material functions and redefined martensite internal variable. Khoo Z. Van Humbeeck J. Shape memory alloys: A material and a technology. Icardi U. Preliminary study of an adaptive wing with shape memory alloy torsion actuators.
Coutu D. Implant Materials. We offer casting supplies at prices that can't be beat. The orthopedic bed is one of the finest materials that you can lay your hands on the market, and it does not lose it shapes easily. Claremont, NH Fax www. This lift is also called orthopedic shoe lift inserts that are used in one shoe where elevation of the heel is needed for treatment.
Orthopedic Materials Diabetic inlays 17 Our team has great expertise in the pedorthic world, as well as experience in manufacturing, selling, distributing and developing pedorthic accessory products. Fracture splints are the methods and materials to immobilize the fracture for transport when fracture or break in the bone can result from an injury. At present, strong requirements in orthopaedics are still to be met, both in bone and joint substitution and in the repair and regeneration of bone defects.
We've got men's orthopedic shoes made from a variety of materials such as leather, oiled leather, suede leather, anti-microbial fabric, and air mesh. OIC is a company with a revolutionary idea. We operate a warehouse that makes shipments to dozens of countries each year. Our orthotic materials are based on a Shore A Durometer, which is the standard of measurement for orthopedic materials.
Orthopedic products are, first and foremost, tailored to specific bodyparts, such as the wrist, knee and ankle. Minor, Alegria by P. While the materials used for these have a long history of success, a better understanding of the natural structure, makeup, and formation of bone tissue as well as new fabrication techniques, provide the opportunity for developing new materials and improving current technology.
Our proprietary coatings, advanced manufacturing, and full-service options set us apart in the medical device market. We usually split the sole and put the full lift or wedge in the middle of the sole. Our extended hours benefit little leaguers, working parents and weekend warriors. Exercise is often difficult and painful for people suffering from bone and joint problems, for example. Memory foam orthopedic pain relief seat and back support cushion set Black Other. May 30 - June 2, David L.
Services on Demand
If you have an orthopedic issue, such as a sprain, strain, fracture, or an orthopedic pain that just won't go away, we are here to help you. Internal Fixation Hardware. The following knee video materials show the most common knee injuries and conditions, such as ACL tears, meniscus tears, and educate on the treatment options. If a fractured bone can be held together it can regenerate the tissue and regain most of its original strength. The newly emerged field of nanotechnology-enhanced orthopedic materials is an interdisciplinary area of nanotechnology, materials and medical sciences, and orthopedics.
An in-depth analysis on a geographic basis provides strategic business intelligence for healthcare sector investments. At the puppy and senior stages, these hours increase. By providing various materials to the most exacting tolerances, OEMs and Contract Manufacturers enjoy the benefits associated with superior roundness, straightness and runout. MCS product quality and grinding expertise means better surgical outcomes. Select from a wide range of live educational AAOS events, conferences and webinars.
Mayo Clinic has one of the largest and most experienced practices in the United States, with campuses in Arizona, Florida and Minnesota. Orthopedic dog beds are the perfect option for older dogs with hip, joint, bone and mobility issues, as well as dog breeds that are susceptible to these issues as they age. Older populations are at greater risk for arthritis, fall-related injuries, joint replacements, and other orthopedic problems. Find and research local Orthopedic Surgery Specialists, including ratings, contact information, and more.
From diagnosis through treatment, Mayo Clinic orthopedic surgeons at campuses in Minnesota, Arizona and Florida are at the forefront employing advanced technologies in the best interest of Reviews: The Best Orthopedic Walking Shoes. Download this whitepaper to learn about the various biocompatibility and sterilization considerations surrounding 3D-printed orthopedic devices.
Free Online Library: Choosing materials wisely: as orthopedic designs change rapidly, so must orthopedic materials. The in vitro results confirm that the developed bone-cement abides by the standard orthopedic requirements making it apt for real-time prosthetic materials. Screws; Plates; Pins and Wires We repair custom foot orthotics online! The orthopedic devices market exceeded USD We do not sell materials separately.
Made from high-quality materials for durability and comfort. Bell-Horn is a manufacturer and distributor of a full line of retail orthopedic braces, supports and compression hosiery.
In addition, Sawbones is guided by the American Society of Testing Methods ASTM for orthopedic implant testing and device testing, so materials used in creating bone models should meet these rigid requirements. All application materials must be received by January 5 for consideration. Joint replacements, particularly at the hip, and bone fixation devices have become very successful applications of materials in medicine.
See an Orthopedic doctor within 24 hrs. Our purpose is to supply practitioners with the materials they need at the lowest possible price, and with outstanding customer service. No more abrasive, uncomfortable straps. The orthopedic panel covers surgical materials divided into 33 categories used to treat other parts of the body such as hips, elbows, and spines. However, there are still several issues accompanied with the use of prosthetic materials, such as low wear performance and catastrophic failure. The DePuy Synthes Companies deliver innovative medical devices and solutions in orthopaedics, spinal care and neuroscience that help patients live full lives.
Knee and hip braces to implantable devices in knee, hip, hand, foot and spine. I am very happy to say that OIC products are used in my facility. Structural integrity implies a combination of fracture toughness, strength, ductility, and hardness, and also time-dependent properties and fatigue FIG. The material of the screws is highly non-reactive does not cause any allergic or corrosive reactions inside the body. All of these are podiatrist recommended and come in numerous styles, colors, and sizes. If you can't find the orthopedic supplies you are looking for, please give us a call and we'll find it!
The base metal s are found in the highest quantities, but smaller amounts of other metals are also found in the implant. Adaptation of these findings by current orthopedic residents may have a positive impact on OITE performance. Orthopedic back braces and supports help those who have suffered a back injury or who have to deal with chronic back pain. Orthopedic shoe lifts can be added to almost any type of shoe. However, for the medical sector, although feasible, applications and actual products taking advantage of this technique are only scarcely reported.
Current orthopedic supplies at discount prices. Support — Orthopedic sandals like orthopedic shoes are generally good for your feet, with the arch, heel, and overall support that they provide they allow your feet to maintain their correct natural shape when you wear them. Our materials are grown and produced without the use of toxic chemicals, so they do not cause harm to your pets, farmers, or the planet.
Putting the lift in between helps keep the original look of the shoe and enhances the durability of the lift. Watch the pre- and post-surgery videos your doctor prescribes. In addition, reviewing these materials does not guarantee that candidates will receive a passing score on the specialist certification exam. We provide reliable, independent, confidential testing that follows applicable standardized or custom test methods to clients in need of additional testing capacity.
These are Therapeutic Orthopedic work boots with Extra Depth for advanced comfort and support. Close collaboration between OEMs and suppliers is the best way to keep pace. The demand for orthopedic nurses is likely to increase, based on the increase of the aging population in the United States.
Wayne State University, Detroit, Michigan. A fracture occurs when a force acts on bone and bone can not effectively resist the force and gives way. The primary function of orthopedic materials is to bear load and provide structural integrity to the human body. Table 4. Why not make orthopedic implants affordable for both healthcare providers and patients? The OIC products are high quality and easy to use by our surgeons. This is an ideal book for graduate students, researchers and professionals working with orthopedic biomaterials and tissue Custom Fabrication Services.
Who should go to the Injury Clinic? The Injury Clinic sees patients ages 5 and older. An overview is reported about the history of prevailing magnesium alloys as orthopedic biodegradable materials. Narang Medical Ltd. McBride Orthopedic Hospital is nationally recognized as a leader in orthopedics and sports medicine. They are commonly used after serious knee injuries such as ligament tears, or after certain types of knee surgery such as an ACL reconstruction.
Casting Supplies. In such a case, an orthopedic expert is able to recommend the best type of pillow. When even one of these important components is affected by an injury that needs orthopedic surgery or a medical condition, the entire body can suffer. At Mayo Clinic, your team of orthopedic surgery experts uses the latest techniques and technology to improve care for people with musculoskeletal problems.
We do not sell directly to patients. Nanotechnology-Enhanced Orthopedic Materials.
Refine Search. Do you need to return to work, improve your athletic performance, or recover from an injury? Our orthopedic surgeons, physiatrists, family medicine physicians, and therapists work with you to create custom treatment plans and get you the best care available. Bone tissue, unlike most of the body's tissues, has the remarkable ability to regenerate itself.