مکانیسم شکست برشی بلوک از گروه های بار محوری پیچ ها
ترجمه نشده

مکانیسم شکست برشی بلوک از گروه های بار محوری پیچ ها

عنوان فارسی مقاله: مکانیسم شکست برشی بلوک از گروه های بار محوری پیچ ها
عنوان انگلیسی مقاله: Block shear failure mechanism of axially-loaded groups of screws
مجله/کنفرانس: سازه های مهندسی - Engineering Structures
رشته های تحصیلی مرتبط: مهندسی عمران
گرایش های تحصیلی مرتبط: سازه
کلمات کلیدی فارسی: پیچ های شیاربند خودکار، گروه های بار محوری پیچ ها، مکانیسم شکست، بلوک شکست برشی، مدل فنر، اثر گروه
کلمات کلیدی انگلیسی: Self-tapping screws، Axially-loaded groups of screws، Failure mechanisms، Block shear failure، Group effect
نوع نگارش مقاله: مقاله پژوهشی (Research Article)
نمایه: Scopus - Master Journals List - JCR
شناسه دیجیتال (DOI): https://doi.org/10.1016/j.engstruct.2018.12.057
دانشگاه: Competence Center holz.bau forschungs gmbh, Inffeldgasse 24/I, 8010 Graz, Austria
ناشر: الزویر - Elsevier
نوع ارائه مقاله: ژورنال
نوع مقاله: ISI
سال انتشار مقاله: 2019
ایمپکت فاکتور: 3/604 در سال 2018
شاخص H_index: 114 در سال 2019
شاخص SJR: 1/628 در سال 2018
شناسه ISSN: 0141-0296
شاخص Quartile (چارک): Q1 در سال 2018
فرمت مقاله انگلیسی: PDF
تعداد صفحات مقاله انگلیسی: 23
وضعیت ترجمه: ترجمه نشده است
قیمت مقاله انگلیسی: رایگان
آیا این مقاله بیس است: خیر
آیا این مقاله مدل مفهومی دارد: ندارد
آیا این مقاله پرسشنامه دارد: ندارد
آیا این مقاله متغیر دارد: ندارد
کد محصول: E11501
رفرنس: دارای رفرنس در داخل متن و انتهای مقاله
فهرست انگلیسی مطالب

Abstract


1- Introduction


2- Block shear model


3- Setting of model parameters


4- Experimental investigations


5- Results and discussion


6- Summary, conclusions & outlook


References

نمونه متن انگلیسی مقاله

Abstract


Self-tapping screws are fasteners that are versatilely applicable in timber engineering. For the design of such screw connections, preferential axial-loading, all possible failure mechanisms have to be considered. Recently, in compact groups of axially-loaded screws the block shear failure mechanism, which has not been investigated so far, turned out to fail rather brittle at load levels lower than currently allowed. This failure mechanism is defined as failure of (rolling) shear and/or tension perpendicular to grain planes encompassing the group of screws. This failure mechanism was observed in groups given a number of different parameter settings, i.e. thread-fibre angles of 90° and 45°, glulam, structural timber and cross laminated timber and various group designs. This paper focuses on groups of axially-loaded screws in glulam and solid timber of Norway spruce (Picea abies) and inserted at a thread-fibre angle of 90°. Varying group sizes, loading and supporting distances and group designs, i.e. various penetration lengths lef and spacing in and perpendicular to grain, a1 and a2, respectively, are analysed by two different “push-pull”-test setups. To predict the block shear capacity and failure characteristics of such groups of screws and to separate this failure mechanism from other failure mechanisms, a mechanical-based block shear model was established. This parallel acting spring model considers load sharing and redistribution between concerned failure planes and depends on a number of material, geometrical and stress distribution parameters. To ensure a reasonable parameter setting, background and potential influencing parameters on each model parameter are discussed. In validation, the model shows overall good predictions of capacities, failure mechanisms and failure sequence for all test series involved. It turned out that the current regulations, comprising the definition of minimum spacing together with minimum edge and end distances, are not sufficient for controlling this three-dimensional block shear failure. In addition, the consideration of the number of screws in the group as well as the penetration length is required.


General comments


In contemporary timber engineering, dowel-type fasteners are differentiated in fasteners primary stressed in shear, e.g. dowels or nails, or axially in tension or compression, e.g. self-tapping screws or glued-in rods. Whereas in the first group the timber is primary stressed in compression, in the second group the timber is primary stressed in shear. Self-tapping screws are optimised for load-bearing purposes axial in tension, as addressed in this study, made of hardened steel and feature high resistance and stiffness but only minor plastic deformability until failure. The versatile possibilities how to apply them can be differentiated in ”active applications”, i.e. for connecting structural elements, and in ”passive applications”, i.e. for reinforcing structural elements; see Ringhofer et al. [1] and Ringhofer [2]. Active applications with several screws are realised often with outer steel plates, as exemplarily shown in Fig. 1. Differentiation can be made in (i) joints with steel plates constantly pressed on the timber surface, i.e. joints featuring a restricted deformability of the timber surface as shown in Fig. 1(b), named further as ”restricted joints”, and in (ii) joints with steel plates constantly taken-off from the timber surface, see Fig. 1(c), named further as “free joints”. We further concentrate on “free joints” of primary axially and in tension loaded self-tapping screws, thus possible positive effects on the resistance of restricted joints are excluded.

  • اشتراک گذاری در

دیدگاه خود را بنویسید:

تاکنون دیدگاهی برای این نوشته ارسال نشده است

مکانیسم شکست برشی بلوک از گروه های بار محوری پیچ ها
نوشته های مرتبط
مقالات جدید
نماد اعتماد الکترونیکی
پیوندها