BACKGROUND The current study was carried out to compare the amount of tooth movement during canine retraction comparing two different retraction mechanics; friction mechanics represented by a NiTi closed coil spring versus frictionless mechanics represented by T - loop, and their effect on root resorption using Cone Beam Computed Tomography (CBCT). METHOD Ten patients were selected in a split...

Introduction and Aim. Exceptional properties of the NiTi archwires may be jeopardized by the oral cavity; thus its long-term effect on the mechanical and physiochemical properties of NiTi archwires was the aim of work. Material and Methods. Study group comprised sixty 0.016 × 0.022 NiTi archwires from the same manufacturer evaluated (group A) after the first 12 weeks of orthodontic treatment. 3...

Thin-film shape memory alloys (SMAs) have become excellent candidates for microactuator fabrication in MEMS. We develop a material model based on a combination of free energy principles in combination with stochastic homogenization techniques. In the first step of the development, we construct free energies and develop phase fraction and thermal evolution laws for homogeneous, single-crystal SM...

A new membrane actuator based on our previous diaphragm actuator was designed and constructed to improve the dynamic performance. The finite element analysis was used to estimate the frequency response of the composite membrane which will be driven close to its resonance to obtain a large stroke. The membrane is made of ferromagnetic shape memory alloy (FSMA) composite including a ferromagnetic...

In this chapter, a three-dimensional phenomenological constitutive model for the simulation of shape memory alloys is introduced. The proposed macromechanical model is based on microplane theory. Microplane approach is chosen to have limited material parameters in that all of those are measurable by simple tests. User material subroutine is developed to implement the proposed model in a commerc...

This study investigates the optimum design parameters of a superelastic friction base isolator (S-FBI) system through a multi-objective genetic algorithm to improve the performance of isolated buildings against near-fault earthquakes. The S-FBI system consists of a flat steel-PTFE sliding bearing and superelastic NiTi shape memory alloy (SMA) cables. Sliding bearing limits the transfer of shear...

Obtaining a reliable NiTi to Ti6Al4V dissimilar joint exhibiting NiTi's superelasticity can provide design flexibility in aerospace and biomedical fields via integrating distinct material benefits. However, this materials couple is vulnerable severe embrittlement due the development of excessive intermetallic compounds (IMCs), namely Ti2Ni. Pd-free Pd-interlayered NiTi-Ti6Al4V laser joints were...