Browse Topic: Dimensional inspections
In area of modern manufacturing, ensuring product quality and minimizing defects are utmost important for maintaining competitive advantage and customer satisfaction. This paper presents an innovative approach to detect defect by leveraging Artificial Intelligence (AI) models trained using Computer-Aided Design (CAD) data. Traditional defect detection methods often rely on physical inspection, which can be time-consuming and prone to human error. The conventional method of developing an AI model requires a physical part data, By utilizing CAD data, the time to develop an AI model and implementing it to production line station can be saved drastically. This approach involves the use of AI algorithms trained on CAD models to detect and classify defects in real-time. The field trial results demonstrate the effectiveness of this approach in various industrial applications, highlighting its potential to revolutionize defect detection in manufacturing.
The light and light signaling devices installation test as per as per IS/ ISO 12509:2004 & IS/ISO 12509:2023 for Earth Moving Machinery / Construction Equipment Vehicles is a mandatory test to ensure the safety and comfort of both road users and operators. Considering the shape and size of construction equipment vehicles, accurate measurement of lighting installation requirements is crucial for ensuring safety and regulatory compliance. The international standard IS/ISO 12509:2004 & IS/ISO 12509:2023 outlines specific criteria for these installation requirements of lighting components, including the precise measurement of various dimensions to ensure optimal visibility and safety. Among these dimensional requirements, the dimension 'E' i.e., the “distance between the outer edges of the machine and the illuminating surface of the lighting device” plays a critical role in the performance of vehicle lighting systems. Traditional methods of measuring this dimension, such as using a measuring tape and long straight rod, in another method Using Rope, Plumb and Measuring tape have limitations in terms of precision and consistency due to machine size and shape. This paper presents a method development approach utilizing a 3-Dimensional planar laser for measuring dimension 'E' in Construction Equipment Vehicles (CEVs). Measurement through the planar laser method is found to offer significantly higher accuracy compared to conventional measuring techniques, particularly when applied to the complex shapes and sizes of CEV’s such as Motor Graders, Wheel Loaders and Backhoe Loaders. This approach not only enhances the measurement accuracy but also improves the efficiency of the testing process. The paper discusses the methodologies, results, comparison of 3 measuring methods and potential applications of Planar laser in the context of IS/ISO 12509:2004 & IS/ISO 12509:2023, offering a promising alternative method for future testing and certification of Construction Equipment Vehicle’s lighting systems.
As part of a larger project aimed at gaining a better understanding of factors that affect the quality of test results using anthropomorphic test devices (ATDs), the FAA tested the effects of dynamic loading of an ATD pelvis. The ATDs required in the aviation regulations were initially developed for the automotive crash environment, which does not include a vertical testing component. One of the two dynamic tests is a vertical impact, with the principal measurement being the compressive load in the lumbar spinal column, with a regulatory limit of 1500 lb. The lumbar load cell is mounted to the pelvis, and data collected could be affected by the performance of the ATD pelvis. The ability to define a vertical calibration test could be used to determine if the pelvis is acceptable for initial use or to monitor in-service degradation. Three ATD pelvises were compressed in a high-rate load frame. The peak load and loading rate of the pelvis compression were selected to simulate conditions achieved in transport category aircraft vertical seat testing. The primary test objective was to measure changes to the rubber and foam cover of the metallic pelvis during high cyclic loading. Each pelvis was subjected to over 100 cycles. Static dimensional measurements, based on a manufacturing tolerance evaluation, were collected during testing. The high-cycle testing did not deform the foam and rubber covers enough to exceed the total dimensional tolerance of the pelvises (± 0.120 in.). The appearance of visual damage was closely monitored throughout the testing. Similar visual damage was seen for each pelvis and occurred at low cycles — 15 to 30. Results suggest the appearance of damage minimally changed the dynamic response of the pelvis. Force-deflection data were also collected from each test series. These data showed minimal change during testing, with the deflection at 2000 lb. changing approximately 0.100 in. across the 105 cycles. This value is similar to the manufacturer’s tolerance for the height of the pelvis. Based on this, the number of vertical sled tests that would precipitate replacement may be over 100 cycles. Due to the harsh environment of dynamic sled testing, other factors, such as cuts in the foam and rubber due to belt loading, may trigger the removal of an ATD pelvis from service prior to the pelvis reaching a defined number of cycles. Future FAA research will evaluate how this change in pelvis force-deflection affects lumbar load.
Additive manufacturing (AM) is currently being used to produce many aerospace components, with its inherent design flexibility enabling an array of unique and novel possibilities. But, in order to grow the application space of polymer AM, the industry has to provide an offering with improved mechanical properties. Several entities are working toward introducing continuous fibers embedded into either a thermoplastic or thermoset resin system. This approach can enable significant improvement in mechanical properties and could be what is needed to open new and exciting applications within the aerospace industry. However, as the technology begins to mature, there are a couple of unsettled issues that are beginning to come to light. The most common question raised is whether composite AM can achieve the performance of traditional composite manufacturing. If AM cannot reach this level, is there enough application potential to warrant the development investment? The answers are highly dependent on the individual processors and will require significant research. Yet, there are still other common challenges that are not isolated to a singular processor. The focuses of this chapter are the capability to design and provide robust structural analysis for continuous fiber-reinforced polymer AM—two unsung aspects that can make or break this new technology as it finds its way into the aerospace market. These two unsettled issues, out of many, may require fundamental changes to the design, analysis, and manufacturing process. Without solutions to them, adoption by the aerospace industry will be limited to point design applications, thus constraining the technology to being nothing more than a specialized tool.
In the 1990s and early 2000s, the field of parallel kinematics was viewed as being potentially transformational in manufacturing, having multiple potential advantages over conventional serial machine tools and robots. Many prototypes were developed, and some reached commercial production and implementation in areas such as hard material machining and particularly in aerospace manufacturing and assembly. There is some activity limited to niche and specialist applications; however, the technology never quite achieved the market penetration and success envisaged. Yet, many of the inherent advantages still exist in terms of stiffness, force capability, and flexibility when compared to more conventional machine structures. This chapter will attempt to identify why parallel kinematic machines (PKMs) have not lived up to the original excitement and market interest and what needs to be done to rekindle that interest. In support of this, a number of key questions and issues have been identified which need to be explored to advance the technology further. In this chapter, we establish the history and current state of the art of PKMs and identify key issues that unlock the technology’s potential. We have sought the views of recognized thought leaders to understand the practical limitations that have hindered deployment and what, if anything, can be done to move the technology forward given the prospective advantages.
Connecting rod of a high performance reciprocating internal combustion engine is one of the critical components exhibiting complex motion. This is subjected to both compressive load due to combustion force as well as tensile load due to inertia of the moving components. These loadings are cyclic in nature and the component is highly prone to fatigue failure if not deigned or manufactured carefully. Therefore connecting rods are designed and manufactured with high degree of precision for infinite loading cycle. But failures in connecting rod is often reported which is associated to either fatigue, bending, bearing failure or assembly faults. This study deals with one of such failure of connecting rod reported during fatigue testing. Failures occurred at around 1 million fatigue loading cycle as against target life of 5 million cycles. The present study represents the investigations done for engine connecting rod and with a view to identify the root cause of failure. Factors affecting failure including structural design, type of material and dynamic loads were assessed using standard failure analysis method. This included Visual observation, metallurgical testing, magnetic particle testing, fractography analysis by stereo and scanning electron microscopy, residual stress analysis, dimensional inspection, chemical analysis, Brinell hardness testing, tensile testing, inclusion analysis, microstructure analysis and grain flow analysis. Results of this investigation suggest that the connecting rod has failed due to improper machining/drilling of oil hole and chamfer at the small end of connecting rod which had generated rough tool marks at inner diameter, serration marks and material chip off. This induced harmful tensile residual stresses which resulted in early fatigue failure.
Researchers at NASA's Marshall Space Flight Center have developed a novel method for interim, in-situ dimensional inspection of additively manufactured parts. Additive manufacturing processes currently have limited monitoring capabilities, offering users little to no options for mitigating the high levels of product and process failures.
Straightness uncertainty in dimensional metrology is an important parameter in precision engineering. Optimization in straightness measurement using soft algorithm techniques is widely encountered solution in coordinate metrology. In this work, we report on the uncertainty in the CMM measurement of straightness feature for a slab surface. Straightness points have been measured precisely in 3D using CMM at NIS. The straightness has been analyzed using a Particle Swarm Optimization (PSO) algorithm. The probability density distribution of the measured spatial straightness was developed using a Sequential Monte Carlo (SMC) technique; forming probability density histogram with 95% confidence level representing an uncertainty in the straightness measurement. Comparison with relevant reports showed and approved that our results are more accurate since we used a computationally efficient modified SMC technique and PSO algorithm. This work confirms that the developed strategic methodology can achieve validation method successfully for straightness uncertainty. Moreover, uncertainty in straightness measurement has been estimated and found to be suitable of the proposed validation method for CMM dimensional metrology.
ABSTRACT Composite helicopter tailboom frames were manufactured by compression molding using a carbon fiber thermoset bulk molding compound. A mold was designed for compression molding and installed in a hydraulic press. The mold features two shear edges, guide pins and an integrated part ejection system. A material preforming method was developed to improve consistency in material distribution, which improved process robustness. A number of parts were produced and inspected for void content and dimensional stability. No significant porosity or voids were found in the samples examined. Part thickness uniformity was studied and improved, in order to meet the required tolerances. Dimensional inspection before and after a free standing post cure showed no significant part distortion. This work showed that compression molded tailboom frames are a viable alternative to current tailboom frames using continuous pre-impregnated fabric materials and cured by autoclave. This alternate processing method has the potential to reduce touch time and manufacturing costs.
Composite production rates will need to increase markedly to meet future demand, especially in the case of mainstream automotive. Coupled with that is need to keep quality levels high and costs down. Scrap represents a large portion of this cost and should be minimised. Due to the complexities of composite manufacture there are numerous sources of variation. These variations mean that a composite part cannot be considered to be “flawless”. Instead acceptable levels of variation are established. These requirements govern whether or not a part is scrapped based on a set of measurements. These measurements are carried out assuming that there are no flaws arising from the design of the part. This paper details the attempt to manufacture a flat panel followed by some more complex features in order to determine if the acceptance criteria can be rigidly adhered to. Using a process map developed from previous work the phases of manufacture are detailed and their potential sources of variability. The results are that even a flat panel cannot be made due to highly stringent ply position requirements stated in the acceptance criteria. Increasing the complexity of the geometry resulted in fibre orientation measurements which could not guarantee that the whole part was within tolerance for fibre angle. It was discovered that there is no in-process definition of thickness, bridging or wrinkling. This means that these features will only be captured in a final dimensional inspection after curing. At this stage the part has attained its maximum embedded cost.
Nowadays, optimization of manufacturing and assembly operations requires taking into account the inherent processes variations. Geometric and dimensional metrology of mechanical parts is very crucial for the aerospace industry and contributes greatly to its. In a free-state condition, non-rigid parts (or compliant parts) may have a significant different shape than their nominal geometry (CAD model) due to gravity loads and residual stress. Typically, the quality control of such parts requires a special approach where expensive and specialized fixtures are needed to constrain dedicated and follow the component during the inspection. Inspecting these parts without jig will have significant economic impacts for aerospace industries, reducing delays and the cost of product quality inspection. The Iterative Displacement Inspection (IDI) algorithm has been developed to deal with this problem. In this paper, we propose a statistical approach based on the extreme value analysis to improve the identification module of the IDI. We tested our robust IDI algorithm on a simulated aerospace sheet metal part. The experiments show that the proposed approach is more robust and effective and extends the original IDI identification module in its methodology and applications.
Machine vision has become indispensable in today’s highly automated manufacturing environments, which rely on accurate in spec tion to ensure high product quality and high process efficiency. Applications for the technology span industry, and include everything from validation of printed barcodes and text on consumer product labeling, to assembly verification of printed circuit boards, to dimensional measurement of automotive parts. The demand for vision inspection only continues to grow with increasing throughput requirements and stringent quality standards that necessitate full inspection and render manual product inspection unfeasible.
A typical aerospace part will be designed, planned, programmed, tooled, reviewed and then qualified using a first article inspection process before it is produced. Using this traditional methodology, it is common to expend large amounts of resources planning a part only to have to modify the manufacturing planning based on the outcome of the first article. This is a costly and time-consuming activity. It is also possible, based on the number of similar parts and the number of planners, to have near identical parts planned differently. This is unfortunately common when there are a lot of very similar parts across a company's product offerings. Companies who lack standard engineering producibility processes as well as standard manufacturing planning processes will also face increased production costs due to variation amongst similar parts. Using an integrated manufacturing planning approach, these costs can be minimized.
This SAE Aerospace Standard (AS) establishes documentation requirements for the First Article Inspection (FAI).
This SAE Aerospace Standard (AS) establishes documentation requirements for the First Article Inspection (FAI).
Measurement of dimensional characteristics of airfoil parts is primarily a manual, labor intensive operation. It employs a wide variety of gages that vary from very expensive optical comparitors to inexpensive pin gages. An automatic non-contacting inspection gage capable of measuring most dimensional characteristics would be cost effective, simplify inspection operations, consolidate a number of gages into one, and improve overall inspection reliability by minimizing human involvement. This paper presents the results of the design and development of a demonstrator semi-automatic laser gage dimensional inspection system that addresses this problem.
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