scholarly journals Design and manufacture of the novel drum worm pair

2020 ◽  
Vol 103 (4) ◽  
pp. 003685042098122
Author(s):  
Jingzi Zhang ◽  
Jin’ge Wang ◽  
Kai Wang
Keyword(s):  
Contact Stresses ◽  
Primary Objective ◽  
Structure Design ◽  
Worm Gear ◽  
The Novel ◽  
Bending Stress ◽  
Manufacturing Method ◽  
Design And Manufacture ◽  
Maximum Contact ◽  
Worm Drive

Although a significant amount of research on robot joint reducer was conducted, there are few systematic investigations on a novel joint reducer adopting inner worm-gear plane enveloping drum worm drive. To satisfy the development of modular robot joint, the primary objective of this paper was to systematically investigate the drum worm drive adopted in the novel joint reducer with integrated structure of drive, transmission, and support in the following aspects: meshing theory, design, analysis, and manufacture. According to the gear meshing theory, mechanical design method, classical mechanics, finite element method, and machining principle of virtual center distance, the systematic investigations around the drum worm pair applied in the novel joint reducer were conducted including the macro and micro meshing theory, structure design, mechanical and contact properties analyses, and manufacturing method. The novel joint reducer’s integrated structure was designed, and the drum worm pair’s mechanical and contact properties analyses were conducted, which showed: (1) the worm’s bending stress and deflection, worm-gear teeth’s shear stress and bending stress as well as the maximum contact stresses were all below their corresponding allowable values; (2) the maximum contact stresses appeared at the engage-in position of the worm pair opposing to the engaging-out position where the largest contact areas appeared. Then the manufacturing of drum worm’s spiral tooth was conducted via the modified 4-axis linkage CNC grinder according to the conjugate motion. Finally the novel joint reducer’s industrial prototype was assembled. The novel joint reducer with integrated structure of drive, transmission and support was designed and manufactured for the first time. The flowchart of design and manufacture of the reducer’s drum worm pair in this process was formulated, which provides a new insight on the research of joint reducers as well as other fields.

scholarly journals Development of a nomogram to predict the contact stress between an I-girder and a support roller

2021 ◽  
Vol 9 (4) ◽  
pp. 377-390 ◽  
Author(s):  
Thanin Chanmalai ◽  
Byungik Chang ◽  
Kevin Misaro ◽  
Saron Hagos ◽  
Thippesh Bethur Hanumanthareddy
Keyword(s):  
Numerical Modeling ◽  
Contact Stress ◽  
Contact Stresses ◽  
Primary Objective ◽  
Steel Bridge ◽  
Element Analysis ◽  
Maximum Contact Stress ◽  
Environmentally Sensitive Areas ◽  
Support Roller ◽  
Maximum Contact

The incremental launching method (ILM) is an efficient method of bridge construction primarily suited for environmentally sensitive areas. However, during the bridge launching, there are significant contact stresses between the launching system and the steel bridge girders. These substantial contact stresses can cause damage both on, and just under, the girder surface. Although Hertz contact theory solutions may give an insight into the problem, the accuracy is uncertain due to the presence of complex geometries, loads, and material properties. The complicated structural systems need to rely on numerical modeling such as the finite element analysis which are not always available. The primary objective of this study is to estimate the relationship of the maximum contact stress between an I-girder and a roller using a nomogram. The nomogram is built based on a parametric study with various roller dimensions and loads by numerical modeling. The maximum contact stress from the nomogram can be a useful tool in designing a bridge girder on a support roller.

Hierarchical Nano/Micro-structured Surfaces with High Surface Area/Volume Ratios

2021 ◽  
pp. 1-36
Author(s):  
Ketki Lichade ◽  
Yizhou Jiang ◽  
Yayue Pan
Keyword(s):  
Surface Structure ◽  
Surface Area ◽  
Light Trapping ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Structure Design ◽  
Surface Structures ◽  
Structured Surfaces ◽  
Design And Manufacture

Abstract Recently, many studies have investigated additive manufacturing of hierarchical surfaces with high surface area/volume (SA/V) ratios, and their performance has been characterized for applications in next-generation functional devices. Despite recent advances, it remains challenging to design and manufacture high SA/V ratio structures with desired functionalities. In this study, we established the complex correlations among the SA/V ratio, surface structure geometry, functionality, and manufacturability in the Two-Photon Polymerization (TPP) process. Inspired by numerous natural structures, we proposed a 3-level hierarchical structure design along with the mathematical modeling of the SA/V ratio. Geometric and manufacturing constraints were modeled to create well-defined three-dimensional hierarchically structured surfaces with a high accuracy. A process flowchart was developed to design the proposed surface structures to achieve the target functionality, SA/V ratio, and geometric accuracy. Surfaces with varied SA/V ratios and hierarchy levels were designed and printed. The wettability and antireflection properties of the fabricated surfaces were characterized. It was observed that the wetting and antireflection properties of the 3-level design could be easily tailored by adjusting the design parameter settings and hierarchy levels. Furthermore, the proposed surface structure could change a naturally-hydrophilic surface to near-superhydrophobic. Geometrical light trapping effects were enabled and the antireflection property could be significantly enhanced (>80% less reflection) by the proposed hierarchical surface structures. Experimental results implied the great potential of the proposed surface structures for various applications such as microfluidics, optics, energy, and interfaces.

Development of a Seabed Geomorphology classification approach; aspiring towards a robust tool to support comprehensive and consistent seabed mapping 

2021 ◽  
Author(s):  
Dayton Dove ◽  
Rachel Nanson ◽  
Lilja Bjarnadóttir ◽  
Janine Guinan ◽  
Joana Gafeira ◽  
...  
Keyword(s):  
Classification Scheme ◽  
Primary Objective ◽  
Second Phase ◽  
The Novel ◽  
New Classification ◽  
British Geological Survey ◽  
Origin And Evolution ◽  
Initial Application ◽  
Seabed Mapping ◽  
The Uk

<p>In 2016, through a collaboration between marine mapping programmes in Norway, Ireland, and the UK, we published a new classification scheme to aid the characterisation of seabed geomorphology (Dove et al., 2016). The classification scheme was developed to address shared objectives and challenges in seabed mapping, particularly to enable more consistent classification where required. The novel aspect of this framework was the effort to independently describe seabed features according to their observed physical 1-Morphology, and the more subjective interpretation of their origin and evolution (2-Geomorphology). Initial application of the approach within our own groups and externally proved promising, and through the welcome involvement of colleagues from Geoscience Australia, we continued to progress and improve the approach.</p><p>We are now within the second phase of the project, which involves the development of glossaries for both parts of the classification scheme. The glossary for part-1 Morphology was recently completed and published (Dove et al., 2020). This glossary includes a revised list of feature names, with definitions and representative diagrams for each feature. Feature definitions are in-part drawn from the International Hydrographic Organization (IHO) guide for undersea feature names, which were modified and augmented with additional terms to ensure the final feature catalogue and glossary encompasses the diversity of morphologies observed at the seabed.</p><p>Part-2 Geomorphology glossary is now in development. We anticipate it to be more complicated than the Morphology glossary due to the (often) variable meaning of different terms between different fields and individual scientists. But as for Part 1, our primary objective is to produce a useful and robust framework (applicable from the coastal zone to the abyss), that minimises duplication and/or ambiguity as much as possible. The Geomorphology glossary will include example bathymetry images to add further value.</p><p>Dove, D., Bradwell, T., Carter, G., Cotterill, C., Gafeira Goncalves, J., Green, S., Krabbendam, M., Mellett, C., Stevenson, A., Stewart, H. and Westhead, K., Scott, G., Guinan, J., Judge, M., Monteys, X., Elvenes, S., Maeten, N., Dolan, M., Thorsnes, T., Bjarnadottir, L., Ottesen, D., 2016. Seabed geomorphology: a two-part classification system. British Geological Survey, Open Report OR/16/001.</p><p>Dove, D., Nanson, R., Bjarnadóttir, L.R., Guinan, J., Gafeira, J., Post, A., Dolan, M.F.J., Stewart, H., Arosio, R. and Scott, G., 2020. A two-part seabed geomorphology classification scheme:(v. 2). Part 1: morphology features glossary.</p>

scholarly journals Kinematic Alignment in Cruciate Retaining Implants Improves the Biomechanical Function in Total Knee Arthroplasty during Gait and Deep Knee Bend

2019 ◽  
Vol 33 (03) ◽  
pp. 284-293 ◽  
Author(s):  
Kyoung-Tak Kang ◽  
Yong-Gon Koh ◽  
Ji Hoon Nam ◽  
Sae Kwang Kwon ◽  
Kwan Kyu Park
Keyword(s):  
Stance Phase ◽  
Lateral Collateral Ligament ◽  
Contact Stresses ◽  
Kinematic Alignment ◽  
Collateral Ligament ◽  
Cruciate Retaining ◽  
Lateral Contact ◽  
Lateral Collateral Ligaments ◽  
Total Knee ◽  
Maximum Contact

AbstractKinematic alignment (KA), which co-aligns the rotational axes of the components with three kinematic axes of the knee by aligning the components to the prearthritic joint lines, has been a recently introduced surgical technique. However, whether KA and cruciate retaining (CR) implants provide better biomechanical function during activities than mechanical alignment (MA) in posterior stabilized (PS) implants is unclear. We evaluated the biomechanical functions during the stance phase gait and deep knee bend, with a computer simulation and measured forces in the medial and lateral collateral ligaments and medial and lateral contact stresses in the polyethylene insert and patellar button. The forces on the medial collateral ligament in KA were lower than those in MA in both CR and PS TKA in the stance phase gait and deep knee bend conditions, whereas those on the lateral collateral ligament did not show any difference between the two surgical alignment techniques in the stance phase gait condition. The maximum contact stresses on the medial PE inserts in KA were lower than those in MA in both CR and PS TKA in the stance phase gait and deep knee bend conditions. However, the maximum contact stresses on the lateral PE inserts and the patellar button did not differ between MA and KA. The biomechanical function was superior in KA TKA than in MA TKA, and KA was more effective in CR TKA. This comparison could be used as a reference by surgeons to reduce the failure rates by using KA TKA instead of MA TKA.

Effect of Chemical Etching on Adhesively Bonded Aluminum AA6082

2007 ◽  
Vol 344 ◽  
pp. 669-676 ◽  
Author(s):  
C. Borsellino ◽  
G. Di Bella ◽  
V.F. Ruisi
Keyword(s):  
Chemical Etching ◽  
Adhesive Bonding ◽  
Structure Design ◽  
The Body ◽  
Adhesively Bonded ◽  
Intimate Contact ◽  
Aluminum Sheets ◽  
Design And Manufacture ◽  
Aluminum Substrates ◽  
Aluminum Surfaces

The efforts of new automotive industry are mainly directed towards the substitution of aluminum for steel in the body structure because the aluminum structures are lighter than traditional steel ones and meet the requirements, in terms of both vehicle design and manufacture. However, this substitution is not so automatic, but it is important to study the material properties and the structure design, focusing the attention on the methods of joining. Welding, typical technique to joint steel parts, is particularly difficult when applied on aluminum ones and then, in many cases, the adhesive bonding is preferred. To optimise the joint performances it is necessary to pre-treat the metal surface, not only to remove contaminants, but also to provide the intimate contact needed for the adhesive to successfully bond with the adherent surface. The mere cleaning of aluminum surfaces is not suitable for their bonding due to the oxide layer that naturally occurs on exposure to air so we need to apply a more effective treatment (mechanical or chemical etching) to increase the adhesion capability of the substrates. In this work different adhesive joint configurations (single lap) between aluminum substrates are studied. Two different resins are employed to evaluate the influence of the adhesive on the joint performances. Moreover the aluminum sheets are treated with a chemical etching with two different procedures.

Topological Optimization Design and Manufacture of Microactuator Based on the Nodal Density Method

2007 ◽  
Author(s):  
Zhen Li ◽  
Baoyuan Sun ◽  
Min Qian ◽  
Jun Zhang
Keyword(s):  
Conceptual Design ◽  
Strain Energy ◽  
Optimization Design ◽  
Optimization Method ◽  
Structure Design ◽  
Topological Optimization ◽  
Structural Function ◽  
Micro Actuator ◽  
Nodal Density ◽  
Design And Manufacture

In order to improve the situation that the design of microactuator is mostly based on the intuition and experience of researchers, the method of continuum topology optimization using the nodal density is introduced to the conceptual design of microactuator. This new method can ensure C0 continuity of density field in a fixed design domain. The ratio of mutual energy to strain energy of the mechanism is regarded as the objective function, where, the mutual energy and strain energy describe the kinematic function and structural function of microactuator respectively. The final configuration of microactuator is decided on the guide of conceptual design combined with the given working conditions. The finite element method is applied to analysis the transmission ratio and clamping force of microactuator. The prototype of the microactuator is fabricated by using micro-electroforming and SU-8 photolithography techniques and the displacement of the micro actuator is measured by using the stereo vision microscopy. The experimental results show that the properties of the micro actuator can satisfy the designing demands. This topological optimization method based on nodal density plays an important role in guiding the structure design of micro actuator.

Randomized phase II trial of the carboxylesterase (CES)-converted novel drug EDO-S7.1 in patients (pts) with advanced biliary tract cancers (BTC).

2019 ◽  
Vol 37 (4_suppl) ◽  
pp. 264-264
Author(s):  
Ulrich-Frank Pape ◽  
Stefan Kasper ◽  
Johannes Meiler ◽  
Marianne Sinn ◽  
Arndt Vogel ◽  
...  
Keyword(s):  
Therapeutic Option ◽  
Progression Free Survival ◽  
Best Supportive Care ◽  
Primary Objective ◽  
The Novel ◽  
Treatment Difference ◽  
Randomized Phase Ii ◽  
Significant Efficacy ◽  
Prior Surgery ◽  
Novel Drug

264 Background: The novel drug EDO-S7.1 (CAP7.1) is converted to active etoposide by CES allowing administration of higher doses, reducing resistance, and permitting treatment of advanced tumors. Methods: The primary objective was to compare disease control rate (DCR) in 22 pts with unresectable BTC randomized 1:1 to 3-week cycles of EDO-S7.1 (200 or 150mg/m2; iv) given on days (d) 1–5, or best supportive care (BSC) until progression (assessed every 4 weeks). Secondary objectives were progression-free survival (PFS), time to treatment failure (TTF), overall survival (OS) and safety. BSC pts could crossover to EDO-S7.1 upon progression. Results: DCR favored EDO-S7.1 (55.6% [CI 21.2, 86.3] vs BSC (20.0% [2.5, 55.6]; treatment difference –12.80, 72.39). More EDO-S7.1 treated pts achieved sustainable stable disease (SD) or partial response (PR) vs BSC. Progressive disease occurred in 40% EDO-S7.1 vs 70% BSC pts. Three pts (30%) who progressed on BSC achieved SD following crossover to EDO-S7.1, and one pt (10%) PR (total: 40.0% [12.2, 73.8]) vs two pts with SD following BSC (20.0% [2.5, 55.6]; treatment difference –0.17, 0.57; p=0.0786). Median PFS was 103d with EDO-S7.1 vs 39d with BSC (p=0.006), and median TTF 92d vs 39d, respectively (p=0.006). Median OS was 227d with EDO-S7.1 vs 162d with BSC (p=0.088), and estimated 1-year OS 44% vs 11.3%, respectively. EDO-S7.1 had significant efficacy in pts with metastatic disease (p=0.029) or without prior surgery (p=0.032). Seven pts were eligible for exploratory analysis of tumor CES via immunohistochemistry. 4/7 pts had CES+ tumors and longer median PFS (195d [163, 233]) and OS (302d [214, 838]) vs pts with CES– tumors (46d [46, 83] and 83d [43, 319], respectively). The most common drug-related adverse events (G3–4) (%) were leukopenia 65 (26.1), neutropenia 78.3 (56.5), thrombocytopenia 56.5 (17.4), anemia 52.2 (17.4), alopecia 34.4 (0), fatigue 26.1 (0), and abdominal pain 30.4 (0). Conclusions: EDO-S7.1 demonstrated efficacy in pts with advanced BTC and may provide a new biomarker-guided therapeutic option with stratification by intra-tumor CES assessment. These findings will be explored in a larger patient cohort. Clinical trial information: NCT02094560.

A New Mistuning Form Existed in Periodic Structure-Force Mistuning

2012 ◽  
Vol 229-231 ◽  
pp. 377-381
Author(s):  
Ai Lun Wang ◽  
Jie Chen ◽  
Qian Jin Wang
Keyword(s):  
Periodic Structure ◽  
Vibration Mode ◽  
Structure Design ◽  
Engineering Practice ◽  
Characteristic Vibration ◽  
Natural Parameter ◽  
Mode Localization ◽  
Vibration Localization ◽  
Natural Characteristic ◽  
Design And Manufacture

The mistuning of periodic structure was generally considered to be natural parameter mistuning, such as stiffness mistuning, damping mistuning and mass mistuning. However, in engineering practice, there was another kind of mistuning—force mistuning. Based on a typical concentrated parameter model of periodic structure, the vibration characteristics, such as natural characteristic, vibration mode and vibration localization of periodic structure with different mistuning forms, were compared and analyzed. The results show that, as a new mistuning form, force mistuning won’t bring mode localization, while it could lead to vibration response localization. The results are very important for periodic structure design and manufacture.

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