Browse Topic: Dimensional inspections
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
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
This standard establishes the requirements for performing and documenting FAI. It is emphasized the requirements specified in this standard are complementary (not alternative) to customer and applicable statutory and regulatory requirements
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
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
This standard establishes the baseline requirements for performing and documenting FAI. Should there be a conflict between the requirements of this standard and applicable statutory or regulatory requirements, the applicable statutory or regulatory requirements shall take precedence
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
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
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
This SAE Aerospace Standard (AS) establishes requirements for performing and documenting the First Article Inspection (FAI
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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