Analysis of Corrosion Causes in the Export of a Compressor in the Pipeline of Western China

The field investigation, macro-inspection, thickness measurement, chemical components examination, mechanical characters tests, microstructure, SEM, XRD analysis and soil composition test were carried out, in order to analysis the external corrosion of the L415 pipe line near the compressor outlet. The results showed that the frequent vibration of the compressor outlet could lead to the damage and failure of the anticorrosive layer, which made the steel pipe loses protection and further exposed to the external environment to cause oxygen corrosion. The content of Cl- in soil was higher in the western China, which accelerated the corrosion of pipe. The corrosion acceleration mainly depended on the pipeline temperature and the secondary external anticorrosive layer.

Polymeric ionic liquid–ionic plastic crystal all-solid-state electrolytes for wide operating temperature range lithium metal batteries

Solid polymer electrolytes show flexible mechanical characters, excellent electrochemical properties, and impressive battery performance over a wide temperature range.

Theory and experimental research for the double ended tuning fork in MEMS

Purpose Being the key sensitive elements of the micro-electromechanical systems (MEMS) resonant sensors, performance of the double-ended tuning fork (DETF) will affect precision of the whole sensor greatly. Currently, most of the research on DETF is concentrated on ideal theory or simply mentioned as part of the sensor. But, in most engineering occasions, there exists many factors such as the additional mass, air damping and fabrication process, etc. However, few references are individually aimed at the mechanical characters of DETF. To choose the suitable DETF, it is important to solely research and measure the performance of this element. Design/methodology/approach In this paper, the authors combine the practical engineering applications and deduce the calculation method of sensitive element’s resonant frequency under various circumstances. The authors also design a force-generating system to make the loading simulation and verify the correctness of theory. Findings On the basis of Euler–Bernoulli theory and Rayleigh’s equation, frequency theories of DETF under four different situations have been deduced. A force-generating device is designed and fabricated to measure the mechanical characters of the DETF. The experiments using force-generating system, DETF, the high performance laser vibrometer and oscillograph are carried out. It verifies the correctness of theory. Originality/value Currently, most of the research on DETF is concentrated on ideal theory or simply mentioned as part of the sensor, and few references are individually aimed at the mechanical characters of DETF. Combining the practical engineering applications, the authors deduced the frequency theories of DETF. A force-generating system is designed and fabricated to measure the mechanical characters of the DETF, and the experiment results match the theoretical results very well.

Mechanical Characters of Six Engineering Timoshenko Beams

Timoshenko beam is an extension of Euler-Bernoulli beam to interpret the transverse shear impact. The more refined Timoshenko beam relaxes the normality assumption of plane section that remains plane and normal to the deformed centerline. The manuscript presents some exact concise analytic solutions on deflection and stress resultants of NET single-span Timoshenko beam with general distributed force and 6 kinds of standard boundary conditions, adopting its counterpart Euler-Bernoulli beam solutions. Engineering example shows that scale impact would not unveil itself for micro structure with micrometer μm-order length, yet will be prominent for nanostructure with nanometer nm-order length. When simply supported CNTs is undergone to a concentrative force at the median and complete bend moment, scale action is observed along the ensemble CNTs, while it unfurls itself the most at the position of the concentrated strength. When a clamped-free CNTs is exposed to a centralized force at the mesial and distributed force, there is no scale impact about the deflection at all positions on the left border of the concentrated strength position, while such operation inspires at once at all positions on the right margin of the concentrated strength position. When a clamped-clamped CNTs is lain under a concentrative strength at the middle, the deflection of NET Euler-Bernoulli CNTs reflects scale effect completely. Notable differences between the deflection of Euler-Bernoulli CNTs and that of Timoshenko CNTs are reflected at large ratio of diameter versus length. The deflection of NET clamped-free and simply supported Timoshenko beam doesn’t introduce surplus scale process in terms of its counterpart, NET Euler-Bernoulli beam. However, the deflection of NET clamped-clamped Timoshenko beam does involve additional scale impact solely including the method when the concentrated strength position is at the midway in the beam-length direction.

Determining of Optimized Mechanical Characters for Designing of an Artificial Ankle

Investigating the mechanical behavior of a healthy human ankle shows that it can be simulated by a mechanism composed of simple elements such as spring, and actuator. Hence, appropriate design of this mechanism can be resulted to an artificial ankle that can help amputees properly. Researches show that whatever the biomechanical behavior of artificial ankle is similar to that of natural ankle, it can be used by consuming less energy. Considering biomechanical behavior of normal ankle in a walking gait, required parameters for designing of an artificial ankle composed of springs and electromechanical actuator will be determined. Finally, to verify the suggested model, a prototype will be materialized and tested.

Mechanical Characters Experimental about Reinforced Concrete Profiled Pipe Culvert

It is supposed to be constructed a kind of profiled pipe culvert which have a new type of cross, in view of the reinforced concrete circular culvert’s various diseases that occurred in service of it. In order to know about the mechanical characters of structure, and test the carrying capacity of the profiled pipe culvert, the load test can be used to have a research on the stress, deformation characteristics, and crack distribution and development on the profiled pipe culvert.