Combining Variation Simulation With Thermal Expansion for Geometry Assurance

Author(s):  
Samuel Lorin ◽  
Lars Lindkvist ◽  
Rikard Söderberg ◽  
Robert Sandboge

In every set of assembled products there are geometrical variation and deviations from nominal dimensions. This can lead to products that are difficult to assemble or products not fulfilling functional or aesthetical requirements. In several industries variation simulation is used to predict assembly variation in the development phase. This analysis is usually done under the condition of room temperature only. However, for some materials, such as plastics, the thermal expansion can be significant in the intended environmental span of the product. In an assembly, this can lead to thermal stresses and parts that will deform. To avoid this problem, locating schemes need to be designed to allow for the right behavior while exposed to varying temperatures. In this work the effect of thermal expansion is studied in the context of variation simulation. A virtual tool for this end is also presented. An example from the automotive industry is used where the combined effect of thermal expansion and assembly variation is analyzed. It is shown that it may not be sufficient to simply add the result from thermal analysis to assembly variation. Hence, to assure the geometrical and functional quality of assembled products, during its use, variation simulations need to be combined with thermal stresses.

Author(s):  
Samuel Lorin ◽  
Lars Lindkvist ◽  
Rikard Söderberg ◽  
Robert Sandboge

In every set of assembled products, there are geometrical variations and deviations from nominal dimensions. This can lead to products that are difficult to assemble or products not fulfilling functional or aesthetical requirements. In several industries, variation simulation is used to predict assembly variation in the development phase. This analysis is usually done under room temperature conditions only. However, for some materials, such as plastics, the thermal expansion can be significant in the intended environmental span of the product. In an assembly, this can lead to thermal stresses and parts that will deform. To avoid this problem, locating schemes need to be designed to allow for the right behavior while exposed to varying temperatures. In this work, the effect of thermal expansion is studied in the context of variation simulation. A virtual tool for this purpose is also presented. Two case studies from the automotive industry are used where the combined effect of thermal expansion and assembly variation is analyzed. It is shown that it may not be sufficient to simply add the result from thermal analysis to assembly variation. Hence, to assure the geometrical and functional quality of assembled products during usage variation simulations need to be combined with thermal expansion simulation.


Author(s):  
Ola Wagersten ◽  
Karin Forslund ◽  
Casper Wickman ◽  
Rikard So¨derberg

Perceived Quality clusters different aspects that influence the customer’s perception of non-functional quality on a product that are perceive through senses. All together those aspects and the harmony between them reflect the producer’s ability to control product parameters and thereby also mirror the functional quality of the product. High Perceived Quality cannot be added to the product at the end of the developing process. Project prerequisites, system solution, factory capability etc. are criterion to succeed. Therefore, it is important to be able to evaluate Perceived Quality early in the process when product system solutions and architecture are defined, although data maturity is low. This paper presents a comprehensive framework to manage and support evaluation of Perceived Quality aspects in a product development process. The framework is based on an industrial process in combination with recent research within the field. The framework focuses on activities that can be performed at different stages in the developing process based on maturity of the CAD or styling data. For example, if the styling data is divided into different components by split-lines it has reached higher level of maturity then styling data that not has been divided. Consequently, the choice of applied method is based on data maturity, regardless phase in the developing process. The framework contains methods based on several different simulation and analysis techniques. Design methods, Computer-Aided Tolerancing and FEA based non-rigid variation simulation are represented in the framework.


2021 ◽  
Vol 324 ◽  
pp. 01011
Author(s):  
Eko Prayetno ◽  
Tonny Suhendra ◽  
Jeremya Lukmanto Saputra

Fish is one of the high-protein foods that are very helpful for the development of the human brain. Then, it is necessary to maintain the freshness of the fish for consumption. At this time, fishers and fishmongers preserve the freshness of fish by using Ice in the fish storage. However, it is considered ineffective due to improper ice change time. Therefore, monitoring temperature is very important and helpful to find the right time when replacing the Ice used to ensure the quality of fish. The development of this device uses Arduino ESP32, DHT21 Sensor, Micro SD Module, Internet of Things system, monitoring using Blynk Application and notifications using Telegram App. DHT21 sensor test results obtained a data conformity level (Error Level) of 2%. At the fish storage room temperature, there is the lowest temperature of 10.50 oC and ice temperature conditions in the storage of 0 oC. Therefore, the best state to keep fish fresh that researchers want is 0 oC to 2 oC at ice temperatures or 11.50 oC obtained in testing the time it takes to replace Ice by about 10 hours.


Author(s):  
Cornelia Jareteg ◽  
Kristina Wärmefjord ◽  
Christoffer Cromvik ◽  
Rikard Söderberg ◽  
Lars Lindkvist ◽  
...  

Geometrical variation and deviation in all the manufacturing processes affect the quality of the final product. Therefore, geometry assurance is an important tool in the design phase of a new product. In the automotive and aviation industries where the use of composite parts is increasing drastically, new tools within variation simulations are needed. Composite parts tend to deviate more from nominal specification compared to metal parts. Methods to simulate the manufacturing process of composites have been developed before. In this paper, we present how to combine the process variation simulation of composites with traditional variation simulations. The proposed method is demonstrated on a real complex subassembly, representing part of an aircraft wing-box. Since traditional variation simulation methods are not able to capture the spring-in and the special deviation behavior of composites, the proposed method adds a new feature and reliability to the geometry assurance process of composite assemblies.


Author(s):  
S. Haussühl ◽  
J. Schreuer

AbstractLarge single crystals of optical quality of (±)-tris(ethylenediamine)cobalt(III) nitrate have been grown from aequeous solutions. An X-ray structure analysis yielded space groupPyroelectric, dieletric, piezoelectric and elastic constants have been determined at room temperature. Additionally, we have studied the coefficients of thermal expansion and the thermoelastic constants in the range between 270 K and 350 K. The structure exhibits a nearly trigonal symmetry around the [unk]


Author(s):  
Fredrik Wandeba¨ck ◽  
Rikard So¨derberg ◽  
Johan S. Carlson ◽  
Per-Johan Wahlborg ◽  
Lars Lindkvist ◽  
...  

There is no type of manufacturing process that is not afflicted by variation. Activities intended to ensure the quality of a company’s geometry processes are usually referred to as geometry assurance activities. One clear industrial problem is to understand the relations between the products concept and the manufacturing process. Dimensional data is a very important source of experience of how a product’s geometry has worked in the interaction with the actual manufacturing system. Users therefore need good analysis and presentation tools of geometry outcomes to support both the product developers and production engineers in the analysis of the production output and its consequences. Today the dimensional data can be difficult to obtain or access, and is not necessarily presented in such a way as to provide the user with all necessary information. This paper presents how presentation and analysis tools of geometrical inspection data can be taken a step further. New functionality for feature based 3D visualization of inspection data has been developed which integrates the variation simulation platform and the inspection data database. The goal has been to create better tools for analysis of geometrical variation and increase the understanding of the sources of variation.


Author(s):  
Ruby Annette ◽  
Aisha Banu W ◽  
Subash Chandran P

Cloud services that provide a complete platform for rendering the animation files using the resources in the cloud are known as cloud renderfarm services. This work proposes a multi criteria recommendation engine model for recommending these Cloud renderfarm services to animators. The services are recommended based on the functional requirements of the animation file to be rendered like the rendering software, plug-in required etc and the non functional Quality of Service (QoS) requirements like render node cost, time taken to upload animation files etc. The proposed recommendation engine model uses a domain specific ontology of renderfarm services to identify the right services that could satisfy the functional requirements of the user and ranks the identified services using the popular Multi Criteria Decision Analysis method like Simple Additive Weighting (SAW). The ranked list of services is provided as recommended services to the animators in the ranking order. The Recommendation model was tested to rank and recommend the cloud renderfarm services in multi criteria requirements by assigning different QoS criteria weight for each scenario. The ranking based recommendations were generated for six different scenarios and the results were analyzed. The results show that the services recommended for each scenario were different and were highly dependent on the weights assigned to each criterion.


Author(s):  
Cornelia Jareteg ◽  
Kristina Wärmefjord ◽  
Christoffer Cromvik ◽  
Rikard Söderberg ◽  
Lars Lindkvist ◽  
...  

Geometrical variation and deviation in all manufacturing processes affect quality of the final product. Therefore geometry assurance is an important tool in the design phase of a new product. In the automotive and aviation industries where the use of composite parts is increasing drastically, new tools within variation simulations are needed. Composite parts tend to deviate more from nominal specification compared to metal parts. Methods to simulate the manufacturing process of composites have been developed before. In this paper we present how to combine the process variation simulation of composites with traditional variation simulations. The proposed method is demonstrated on a real complex subassembly, representing part of an aircraft wing-box. Since traditional variation simulation methods are not able to capture the spring-in and the special deviation behavior of composites, the proposed method adds a new feature and reliability to the geometry assurance process of composite assemblies.


1991 ◽  
Vol 30 (01) ◽  
pp. 35-39 ◽  
Author(s):  
H. S. Durak ◽  
M. Kitapgi ◽  
B. E. Caner ◽  
R. Senekowitsch ◽  
M. T. Ercan

Vitamin K4 was labelled with 99mTc with an efficiency higher than 97%. The compound was stable up to 24 h at room temperature, and its biodistribution in NMRI mice indicated its in vivo stability. Blood radioactivity levels were high over a wide range. 10% of the injected activity remained in blood after 24 h. Excretion was mostly via kidneys. Only the liver and kidneys concentrated appreciable amounts of radioactivity. Testis/soft tissue ratios were 1.4 and 1.57 at 6 and 24 h, respectively. Testis/blood ratios were lower than 1. In vitro studies with mouse blood indicated that 33.9 ±9.6% of the radioactivity was associated with RBCs; it was washed out almost completely with saline. Protein binding was 28.7 ±6.3% as determined by TCA precipitation. Blood clearance of 99mTc-l<4 in normal subjects showed a slow decrease of radioactivity, reaching a plateau after 16 h at 20% of the injected activity. In scintigraphic images in men the testes could be well visualized. The right/left testis ratio was 1.08 ±0.13. Testis/soft tissue and testis/blood activity ratios were highest at 3 h. These ratios were higher than those obtained with pertechnetate at 20 min post injection.99mTc-l<4 appears to be a promising radiopharmaceutical for the scintigraphic visualization of testes.


Author(s):  
Nataliia Kharytonova ◽  
Olha Mykolaienko ◽  
Tetyana Lozova

Greening of roads contributes to the protection of roads and their elements from influence of adverse weather and climatic factors; it includes the measures for improvement and landscaping of roads, ensures the protection of roadside areas from transport pollution, provides visual orientation of drivers. The solution of these issues will ensure creation and maintenance of safe and comfortable conditions for travelers. Green plantings in the right-of-way road area include woody, bushy, flower and grass vegetation of natural and artificial origin. For proper operation of public roads and satisfaction of other needs of the industry, there may be the need in removing the greenery. The reason for the removal of greenery in the right-of-way road area may be due to the following factors: construction of the architectural object, widening of the motor road, repair works in the security zone of overhead power lines, water supply, drainage, heating, telecommunications facilities, cutting of hazardous, dry and fautal trees, as well as self-grown and brushwood trees with a root neck diameter not exceeding 5 cm, elimination of the consequences of natural disasters and emergencies. The removal of plantations in the right-of-way area is executed in order to ensure traffic safety conditions and to improve the quality of plantations composition and their protective properties. Nowadays, in Ukraine there is no clear procedure for issuing permits for removing of such plantations. In order to resolve this issue, there is a need in determining the list of regulations in the area of forest resources of Ukraine and, if needed, the list of regulatory acts that have to be improved; to prepare a draft of the regulatory legal act that would establish the procedure of plantations cutting, the methodology of their condition determination, recovery costs determination, the features of cutting. Keywords: plantations, cutting, right-of-way, woodcutting permit, order.


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