Support Bracket Research Articles

Thermal imaging and stress analysis for predicting the behaviour and long-term performance of flare tips

A combination of computational and imaging tools was developed to characterise the performance and assess the lifetime of flare tips, the top portion of stacks used to burn off excess gas in the gas and petroleum industry. Integrating the use of (1) an infrared imaging study to obtain temperature profiles of flare tips in operation and (2) finite element modelling of stress distributions based on temperature profiles allowed lifetime prediction for creep and fatigue failure. The techniques were successfully applied to a complex flare tip design that included a venturi shaped windshield. It was concluded that in this instance, the flare tip lifetime would be limited by a combination of creep and fatigue of the support brackets and by plastic deformation at the top of the windshield. Design methodologies for producing flare tips with improved lifetimes are suggested, including the use of computational fluid dynamics modelling to assess the combined effects of gas flow rates and wind conditions on combustion behaviour. Thus, the prediction prior to installation, of both the performance of a new design and the long-term behaviour, can be a valuable assessment process for a proposed flare tip assembly.

DEVELOPMENT OF A FORCE MEASUREMENT DEVICE FOR LOWER-BODY MUSCULAR STRENGTH MEASURING OF SKATERS

This paper presents a force measurement system that can measure a lower-body muscular strength of skaters. The precise measurement and analysis of the left and right lower-body strength of skaters is necessary, because a left/right lower-body strength balance is helpful to improve the athletes' performance and to protect them from injury. The system is constructed with a skate sliding board, a couple of sensor-units with load cell, indicator and control box, guard, force pad, and support bracket. The developed force measurement system is calibrated by the calibration setup, and the uncertainty of the force sensing unit on the left is within 0.087% and the uncertainty of the force sensing unit on the right is within 0.109%. In order to check the feasibility of the developed measurement device, a kinematic analysis is conducted with skater. As a result, the subject shows the deviation of left and right of 12.1 N with respect to average strength and 39.1 N with respect to the maximum strength. This evaluation results are reliable enough to make it possible to measure a lower-body muscular strength of skaters. The use of this measurement system will be expected to correct the posture of skaters and record the sports dynamics data for each athlete. It is believed that through the development of this equipment, skaters in elementary, middle, high schools, colleges, and the professional level have the systematic training to compete with world-class skaters.

On the Rheocasting of High Integrity Hollow Shape Components for Automotive Applications Using 357 Aluminum Alloy

Recent studies regarding semi-solid casting as a viable alternative to conventional liquid metal casting have been met with considerable interest. The dual nature of semi-solid materials results in a marked decrease in internal defects otherwise associated with conventional casting methods. In recent years, the National Research Council Canada - Aluminum Technology Centre (NRC-ATC) has dedicated itself to better understanding the behaviour of semi-solid aluminum alloys, notably 357, using the SEED (Swirled Enthalpy Equilibration Device) rheocasting method. SEED is a novel process which relies on the mechanical agitation and cooling of molten aluminum to produce a semi-solid billet. This billet is then injected into a die to yield the desired cast shape. The current work focuses on the rheocasting of a 357 aluminum alloy support bracket, consisting of four rings. Material flow around a ring is known to result in a welding of the two metal fronts. Traces of porosity and oxides can sometimes be found at the weld, unless preventative measures are taken. These include the use of overflows attached to the ring via a web as well as a careful control of the casting parameters. At NRC-ATC, several parts were rheocast and then subjected to both destructive and non-destructive testing, in an effort to better understand the material flow behaviour around these rings. The results obtained are presented herein.

Study on the Shovel and Support Bracket’s Compensation for Vertical Pose’s Deviation of Roadheader

Automatic directional excavation technology in the coal mine laneway is the important research direction of integrated excavation project. Shovel and support bracket are the most key parts for keeping roadheader body stable in excavation. This paper studies the control ability and extreme position of boom-type roadheader’s shovel and support bracket, to calculate the adjustable vertical angles rang which is realized by shovel and support bracket, expanding roadheader’s automatic compensating excavation ability, meanwhile ensuring body stable. Vertical angle is one of the four kinds of basic body pose deviation parameters. This study is the research basis for the accuracy analysis of boom-type roadheader’s directional excavation. Because the depth that shovel and support brackets’ tip compress into laneway ground, is mainly determined by laneway ground hardness and body weight, and can’t be calculate accurately, paper’s end gives feedback control application of shovel and support bracket according to laneway conditions.

Thermo Mechanical Simulation of the Flue in Coke Dry Quenching Technology

According to the process feature of the coke dry quenching (CDQ), the factors of the destructive mechanism that influence the sequence function properties of the brick were analyzed. The countermeasures have been adopted for the defects of the bricks for CDQ, such as inferior thermal shock stability and short lifetime, etc. In order to search the effect of thermal expansion stress and mechanical load stress on the CDQ, the temperature field and stress field of the flue in the CDQ were analyzed according to the thermal elastic and plastic theory. The Drucker-Prager plasticity model combined with a tension cut-off criterion was described material behavior. All material properties were taken as temperature dependent. The result indicates that the support bracket under high gradient temperature will bring on the highest thermal stress, which is the main reason of fracture of the support bracket. The cycling temperature has the ability to cause repeated crack propagation throughout the whole service period. To solve this problem, the design of the structure, the method of the heat exchange and the properties of the materials will be improved. The obtained results give a good insight into the reasons of material failure and help to find counter-measures for prolonging the lifetime of CDQ.

Reducing Chest Injuries in Automobile Collisions: Rib Fracture Timing and Implications for Thoracic Injury Criteria

The purpose of this study was to quantify the biomechanical response of the human thorax during dynamic shoulder belt loading representative of that seen in a severe automotive collision. Two post-mortem human surrogates (PMHSs) (one male and one female) were instrumented with 26 single-axis strain gages on the ribs, sternum, and clavicle. The thorax of each PMHS was placed on a custom spine support bracket designed to support the thorax on either side of the spinous process, thereby allowing free motion at the costovertebral joints. In addition, the support bracket raised the thorax above the flat base plate, which could otherwise constrain the deformation and motion of the posterior region of the rib cage. The thorax of each PMHS was then loaded using a custom table-top belt loading system that generated thoracic displacement rates representative of a severe automotive collision, 1.3m/s for the male PMHS and 1.0m/s for the female PMHS. The rib fracture timing data, determined by analyzing the strain gage time histories, showed that severe thoracic injury (AIS=3) occurred at 16% chest compression for the male and 12% chest compression for the female. However, these values are well below the current thoracic injury criteria of 29% chest compression for the male and 23% chest compression for the female. This data illustrates that serious thoracic injury (AIS=3) occurs at lower chest compressions than the current ATD thoracic injury criteria. Overall, this study provides critical data that can be used in the design and validation of advanced ATDs and finite element models, as well as the establishment of improved, more stringent thoracic injury criteria.

Want to Know the Best Antenna and Cable Attachment Methods?

The appropriate method for attaching telecommunications antennae and coaxial cable support brackets to water towers is based on numerous factors, including the brackets' purpose, water tank design, and tank structural integrity requirements. Although attachment by seal welding is the method most widely used, this article discusses the three most common attachment methods, including stud welding, bolting, and seal welding. The article discusses a study to determine if stud‐welding or bolting can be used without compromising an owner's facility and still meet tenant scheduling and budget goals. The study incorporated variations to the stud‐welding and bolting fastening sequence and tested five sample bracket attachment methods in a controlled environment that simulated typical exterior exposure. Laboratory testing compared exterior exposure performance of the bracket assembly coating repairs using capacitor‐studs, bolted assemblies, and seal‐welded assemblies. Study conclusions indicate that, because of its structural properties, seal‐welding has been the preferred method for attaching support brackets for telecommunications equipment.

Dynamic interaction of rotating momentum wheels with spacecraft elements

In modern spacecraft with the requirement of increased accuracy of payloads, the on-orbit structural dynamic behavior of spacecraft is increasingly influencing the design and performance of spacecraft. During the integrated spacecraft testing of one of the satellites, a strong coupling between rotating momentum wheels and an earth sensor was detected. This resulted in corruption of the earth sensor data at certain wheel speeds. This paper deals with the dynamic coupling problem of a rotating momentum wheel with its support brackets affecting other subsystems of spacecraft. As part of this investigation, extensive modal tests and vibration tests were carried out on the momentum wheel bracket assembly with wheels in stationary and rotating conditions. It was found that the effects of gyroscopic forces arising out of rotating wheels are significant and this aspect needs to be taken into account while designing the mounting brackets. Results of analysis and tests were used to redesign the bracket leading to a significant reduction in the interaction and associated problems. A procedure for design of a support structure using a low-order mathematical model is also shown.

Portable vibrator for combined testing of instruments and sensors

A small vibrator for combined testing of instruments and sensors is developed on the basis of an inverse piezoelectric effect. The vibrator is a resonant converter with fluctuations in bending that includes a dismountable support bracket for fastening an instrument under test and a built-in piezoaccelerometer for automatic vibration control.

Electroless Ni-P deposition on magnesium alloy from a sulfate bath

A technology for electroless Ni-P deposition on AZ91D from a low cost plating bath containing sulfate nickel was proposed. The seal pretreatment was employed before the electroless Ni-P deposition for the sake of occluding the micro holes of the cast magnesium alloy and interdicting the bubble formation in the Ni-P coating during plating process. And pickling pretreatment can provide a better adhesion between the Ni-P deposition and AZ91D substrate. The deposition speed of the Ni-P coating is 29 μm/h. The technology is employed to AZ91D magnesium alloy automobile parts and can provide high hardness and high wear-resistant. The weight losses of Ni-P plated and heat-treated Ni-P plated magnesium alloy specimen are only about 1/6 and 1/10 that of bare magnesium alloy specimen after 10 min abrasion wear, respectively. The hardness of the electroless Ni-P plated brake pedal support brackets is 674.1 VHN and 935.7 VHN after 2 hours heat treatments at 180 °. The adhesion of Ni-P coatings on magnesium alloy substrates meets the demands of ISO Standards 2819. The technology is environment friendly and cannot cause hazard to environment because of absence of chromate in the whole process.

Application of Integrated Design System Based on Multi-Agent to Assess Cumulative Fatigue Damage of Large Scaled Welded Structure

For the fatigue design of a large scaled welded structure, the readily accessibility of various engineering tools is required for the static, fatigue, dynamic analysis and parametric study. In this paper, a multi-agent system is suggested for the development of distributed, open and intelligent design system. The developed design system is applied to assess cumulative fatigue damage on the welded bogie frame of railway vehicles. The engineering tools for fatigue durability analysis are chosen as I-DEAS, ANSYS and BFAP, in which iterative analysis is performed automatically caused by geometrical changes of transom support bracket attached in the bogie frame. The prototype of design system is implemented successfully for the assessment of cumulative fatigue damages of the welded bogie frame.

Process Integration of Fatigue Analysis for Welded Bogie Frames

The automation of fatigue durability analysis for welded bogie frames according to the UIC-code is proposed by using the ModelCenter, which enables several tools used in fatigue durability analysis to be integrated, i.e. I-DEAS, ANSYS and BFAP, and an iterative analysis of geometrical changes in transom support bracket to be performed. In additions wrapping programs to control I/O-data and interfaces of these tools were developed. The developed automation technique brings not only a significant decrease in man-hour required for durability analysis, but also provides a platform for multidisciplinary engineering activities.

Graphically driven interactive finite element stress reanalysis for machine elements in the early design stage

In this work a new graphically driven interactive stress reanalysis finite element technique has been developed so that an engineer can easily carry out manual geometric changes in a machine element during the early design stage. The interface allow an engineer to model a machine element in the commercial finite element code ANSYS ® and then modify part geometry graphically to see instantaneous graphical changes in the stress and displacement contour plots. A reanalysis technique is used to enhance the computational performance for solving the modified problem; with the aim of obtaining results of acceptable accuracy in a short a period of time in order to emphasize the interactive nature of the design process. Three case studies are considered to demonstrate the effectiveness of the prototype graphically driven reanalysis finite element technique. The finite element type considered is a plane stress four-node quadrilateral based on a homogenous, isotropic, linear elastic material. The first two problems consider a plate with hole and plate with fillets. These two examples demonstrate that by changing the hole and fillet size/shape, an engineer can manually obtain an optimum design based on the stress concentration factor, i.e. engineer-driven optimization process. Each case study considered multiple redesigns. A combined approximation reanalysis method is used to solve each redesigned problem. The third case study considers a support bracket. The goal is to design the cantilever portion of the bracket to have uniform strength and to minimize the stress concentration at the fillet.

Quasi-Rigid Mode of Bond Head Assembly in Wire Bonding Machines and Its Improvement#

In bond head assemblies (BHAs), there exists quasi-rigid vibration mode before 1 kHz, which is caused by the flexibility of its components. This mode hinders the improvement of the servo bandwidth, thus limiting the areal density growth of line pitches. In this paper, the well-designed experiments are carried out to study the dynamic properties of the BHA. It was found that the flexible conjunction due to flexure bearing between BHA and the support bracket, but not the inadequate stiffness of the bond head assembly itself, that caused the first higher resonance as previously thought by most engineers, which limited the servo bandwidth. If the transverse stiffness of the flexure bearing can be improved, the first resonance of the BHA in the wire bonder may be improved greatly. Without changing the flexure pivot and system design, the first higher resonant frequency also can be improved more than 60 Hz through setting the pivot flexure bearing at an approximate optimal angle; this also has been verified by other BHAs.

Independent qualification of phased array inspection of fillet welds

Magnox Generation has investigated whether it is feasible to carry out ultrasonic inspection of welds associated with boiler beam support brackets at various Magnox power stations. The welds are small, with a leg length typically of 6 to 15 mm, and they could not be properly inspected using conventional ultrasonic probes. A technique was therefore developed using a phased array system. This allowed the ultrasonic beam to be focussed electronically, thereby obtaining the required spatial resolution, and also allowed the beam angle to be varied in order to direct the beam into the weld volume between the cap and root. Following the development work, it was decided to apply the technique to some boiler beam support bracket welds at Sizewell A power station. This paper addresses the qualification of the inspection procedure, which TWI managed on behalf of Magnox Generation following the ENIQ methodology. The comprehensive technical justification document was supported by practical trials of the procedure, equipment and individual data analysts. The qualification was completed successfully and confirmed that the procedure was capable of reliably detecting crack-like defects in the weld or heat affected zone greater than 1.5 mm wide by 10 mm long. It also confirmed that, subject to certain provisos, the defect width would not be underestimated by more than 1.5 mm. This qualification involved a novel technique with particular challenges and this paper describes the way in which these were overcome.

Performance of V–4Cr–4Ti material exposed to the DIII-D tokamak environment

As a first step to demonstrate the viability of using vanadium-base alloys for structural applications in fusion devices, six welded upper radiative divertor baffle support brackets made from a V–4Cr–4Ti alloy were installed in the DIII-D tokamak. To determine the effects of exposure to the tokamak environment, lead tests are being conducted on parent metal and weldment specimens. One of the issues to be addressed is whether excessive hydrogen uptake may occur to cause material embrittlement. Some of the lead tests have been completed. Data from samples exposed to up to four DIII-D operating cycles (≈4 years) indicate that the performance of the V–4Cr–4Ti alloy would not be significantly affected by the exposure. Brittle cleavage fractures are noted near the surface of some of the impact specimens, but only at very low (<−150 °C) test temperatures. Above −150 °C, all fractures are ductile.

An Investigation into the Condition Monitoring Strategy for a Large Reversible Francis Pump-Turbine

The authors were asked to devise a strategy for eliciting information from the current vibration monitoring system, which could be utilised in a condition monitoring strategy for the reversible Francis Pump-Turbines located at Dinorwig Power Station, one of the world's largest hydro-electric pump storage schemes. The station consists of six 300MW machines, with each of the 520 tonne assemblies being suspended via a support bracket and a set of oil lubricated thrust bearing pads. Dinorwig performs a critical role in the UK National Grid system due to its ability to provide almost instantaneous power. Each of the machines must operate under an arduous regime in comparison with thermal base-load units, with each unit performing up to twenty-five mode change sequences per day. The information routinely available to Operations Staff provides only a general indication of machine condition. It was found during the study that the installed transducers and signal processing capabilities were capable of producing data series, which can provide considerable useful information However, this required the introduction of an additional data logger. This paper summaries the results of the preliminary study, outlining the techniques used and describes a number of options for further development in the future.

Increasing the Resistance of Powered Support Brackets

Devices, which make it possible to improve support of the roof in the working space, are considered. The results are presented for modeling the interaction between the beam of the powered support and the roof rocks.

Sensor support brackets

Sensor support brackets

Modefying a Carter Flail Forage Harvester to Stabilize the Weighing System

AbstractThe single bending‐beam load‐cell weigh system that is standard equipment on a Carter flail forage harvester allows the forage collection weigh basket to pitch and sway. This movement can allow some forage to be lost when it is blown past the basket. In addition, this movement requires additional time for the basket to stabilize at the end of each plot before a weight can be recorded. A specialized frame with three bending‐beam load cells was designed and constructed to restrict movement of and to support the forage collection weigh basket. Total cost of materials for this modification was about $750. The modifications can be completed with normal shop tools and are readily interfaced with standard equipment on the Carter harvester. The modified support bracket and weigh system performed well, harvesting nearly 10 000 forage plots annually. Compared with the single bending‐beam load cell weigh system, the modified support bracket and weigh system reduced pitch and sway of the forage collection weigh basket, was equally precise, and required an average of 7 s less for the basket to stabilize at the end of each plot.