{"id":247653,"date":"2024-10-19T16:18:15","date_gmt":"2024-10-19T16:18:15","guid":{"rendered":"https:\/\/pdfstandards.shop\/product\/uncategorized\/bsi-pd-iec-tr-620482011\/"},"modified":"2024-10-25T11:25:42","modified_gmt":"2024-10-25T11:25:42","slug":"bsi-pd-iec-tr-620482011","status":"publish","type":"product","link":"https:\/\/pdfstandards.shop\/product\/publishers\/bsi\/bsi-pd-iec-tr-620482011\/","title":{"rendered":"BSI PD IEC\/TR 62048:2011"},"content":{"rendered":"

This technical report provides guidelines and formulae to estimate the reliability of fibre under a constant service stress. It is based on a power law for crack growth which is derived empirically, but there are other laws which have a more physical basis (for example, the exponential law). All these laws generally fit short-term experimental data well but lead to different long-term predictions. The power law has been selected as the most reasonable representation of fatigue behaviour by the experts of several standard-formulating bodies.<\/p>\n

Reliability is expressed as an expected lifetime or as an expected failure rate. The results cannot be used for specifications or for the comparison of the quality of different fibres. This document develops the theory behind the experimental principles used in measuring the fibre parameters needed in the reliability formulae. Much of the theory is taken from the referenced literature and is presented here in a unified manner. The primary results are formulae for lifetime or for failure rate, given in terms of the measurable parameters. Conversely, an allowed maximum service stress or extreme value of another parameter may be calculated for an acceptable lifetime or failure rate.<\/p>\n

For readers interested only in the final results of this technical report \u2013 a summary of the formulae used and numerical examples in the calculation of fibre reliability \u2013 Clauses 5 and 6 are sufficient and self-contained. Readers wanting a detailed background with algebraic derivations will find this in Clauses 7 to 12. An attempt is made to unify the approach and the notation to make it easier for the reader to follow the theory. Also, it should ensure that the notation is consistent in all test procedures. Clause 13 has a limited set of mostly theoretical references, but it is not necessary to read them to follow the analytical development in this technical report.<\/p>\n

\n

NOTE Clauses 7 to 11 reference the B-value, and this is done for theoretical completeness only. There are as yet no agreed methods for measuring B, so Clause 12 gives only a brief analytical outline of some proposed methods and furthermore develops theoretical results for the special case in which \u03b2 can be neglected.<\/p>\n<\/blockquote>\n

PDF Catalog<\/h4>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
PDF Pages<\/th>\nPDF Title<\/th>\n<\/tr>\n
4<\/td>\nCONTENTS <\/td>\n<\/tr>\n
7<\/td>\nFOREWORD <\/td>\n<\/tr>\n
9<\/td>\n1 Scope
2 Symbols
Tables
\n
Table 1 \u2013 Symbols <\/td>\n<\/tr>\n
11<\/td>\n3 General approach <\/td>\n<\/tr>\n
12<\/td>\n4 Formula types <\/td>\n<\/tr>\n
13<\/td>\n5 Measuring parameters for fibre reliability
5.1 General
5.2 Length and equivalent length <\/td>\n<\/tr>\n
14<\/td>\n5.3 Reliability parameters <\/td>\n<\/tr>\n
15<\/td>\n5.4 Parameters for the low-strength region <\/td>\n<\/tr>\n
17<\/td>\nFigures
\n
Figure 1 \u2013 Weibull dynamic fatigue plot near the prooftest stress level <\/td>\n<\/tr>\n
18<\/td>\n5.5 Measured numerical values <\/td>\n<\/tr>\n
19<\/td>\n6 Examples of numerical calculations
6.1 General
6.2 Failure rate calculations <\/td>\n<\/tr>\n
20<\/td>\nFigure 2 \u2013 Instantaneous FIT rates per fibre km versus time for applied stress\/prooftest stress percentages (bottom to top): 10 %, 15 %, 20\u00a0%, 25 %, 30 % <\/td>\n<\/tr>\n
21<\/td>\nFigure 3 \u2013 Averaged FIT rates per fibre km versus time for applied stress\/prooftest stress percentages (bottom to top): 10 %, 15 %, 20 %, 25 %, 30 %
Table 2 \u2013 FIT rates of Figures 2 and 3 at various times <\/td>\n<\/tr>\n
22<\/td>\nFigure 4 \u2013 Instantaneous FIT rates per bent fibre metre versus time(top to bottom): 10 mm, 20 mm, 30 mm, 40 mm, 50\u00a0mm <\/td>\n<\/tr>\n
23<\/td>\nFigure 5 \u2013 Averaged FIT rates per bent fibre metre versus time for bend diameters (top to bottom): 10 mm, 20 mm, 30 mm, 40 mm, 50\u00a0mm
Table 3 \u2013 FIT rates of Figures 4 and 5 at various times <\/td>\n<\/tr>\n
24<\/td>\n6.3 Lifetime calculations
Table 4 \u2013 FIT rates of Table 3 neglecting stress versus strain non-linearity <\/td>\n<\/tr>\n
25<\/td>\nFigure 6 \u2013 1-km lifetime versus failure probability for applied stress\/prooftest stress percentages (top to bottom): 10 %, 15 %, 20 %, 25 %, 30 % <\/td>\n<\/tr>\n
26<\/td>\nFigure 7 \u2013 Lifetimes per bent fibre metre versus failure probability for bend diameters (bottom-right to top-left): 10 mm, 20 mm, 30 mm, 40 mm, 50\u00a0mm
Table 5 \u2013 One kilometer lifetimes of Figure 6 for various failure probabilities <\/td>\n<\/tr>\n
27<\/td>\nTable 6 \u2013 One-meter lifetimes of Figure 7 for various failure probabilities
Table 7 \u2013 Lifetimes of Table 6 neglecting stress versus strain non-linearity <\/td>\n<\/tr>\n
28<\/td>\nTable 8 \u2013 Bend plus 30 % of proof test tension for 30 years <\/td>\n<\/tr>\n
29<\/td>\n7 Fibre weakening and failure
7.1 General
7.2 Crack growth and weakening <\/td>\n<\/tr>\n
31<\/td>\n7.3 Crack fracture <\/td>\n<\/tr>\n
32<\/td>\n7.4 Features of the general results
7.5 Stress and strain <\/td>\n<\/tr>\n
33<\/td>\n8 Fatigue testing
8.1 General
8.2 Static fatigue <\/td>\n<\/tr>\n
34<\/td>\nFigure 8 \u2013 Static fatigue: applied stress versus time for a particular applied stress
Figure 9 \u2013 Static fatigue: schematic data of failure time versus applied stress <\/td>\n<\/tr>\n
35<\/td>\n8.3 Dynamic fatigue
Figure 10 \u2013 Dynamic fatigue: applied stress versus time for a particular applied stress rate <\/td>\n<\/tr>\n
36<\/td>\nFigure 11 \u2013 Dynamic fatigue: schematic data of failure time versus applied stress rate <\/td>\n<\/tr>\n
37<\/td>\n8.4 Comparisons of static and dynamic fatigue <\/td>\n<\/tr>\n
39<\/td>\n9 Prooftesting
9.1 General
9.2 The prooftest cycle <\/td>\n<\/tr>\n
40<\/td>\n9.3 Crack weakening during prooftesting
Figure 12 \u2013 Prooftesting: applied stress versus time <\/td>\n<\/tr>\n
41<\/td>\n9.4 Minimum strength after prooftesting <\/td>\n<\/tr>\n
43<\/td>\n9.5 Varying the prooftest stress
10 Weibull probability
10.1 General <\/td>\n<\/tr>\n
44<\/td>\n10.2 Strength statistics in uniform tension <\/td>\n<\/tr>\n
46<\/td>\n10.3 Strength statistics in other geometries <\/td>\n<\/tr>\n
47<\/td>\n10.4 Weibull static fatigue before prooftesting <\/td>\n<\/tr>\n
49<\/td>\n10.5 Weibull dynamic fatigue before prooftesting
Figure 13 \u2013 Static fatigue schematic Weibull plot <\/td>\n<\/tr>\n
50<\/td>\nFigure 14 \u2013 Dynamic fatigue schematic Weibull plot <\/td>\n<\/tr>\n
51<\/td>\n10.6 Weibull after prooftesting <\/td>\n<\/tr>\n
54<\/td>\n10.7 Weibull static fatigue after prooftesting <\/td>\n<\/tr>\n
55<\/td>\n10.8 Weibull dynamic fatigue after prooftesting <\/td>\n<\/tr>\n
56<\/td>\n11 Reliability prediction
11.1 Reliability under general stress and constant stress <\/td>\n<\/tr>\n
57<\/td>\n11.2 Lifetime and failure rate from fatigue testing <\/td>\n<\/tr>\n
58<\/td>\n11.3 Certain survivability after prooftesting <\/td>\n<\/tr>\n
59<\/td>\n11.4 Failures in time <\/td>\n<\/tr>\n
60<\/td>\n12 B-value: elimination from formulae, and measurements
12.1 General
12.2 Approximate Weibull distribution after prooftesting <\/td>\n<\/tr>\n
63<\/td>\n12.3 Approximate lifetime and failure rate <\/td>\n<\/tr>\n
64<\/td>\n12.4 Estimation of the B-value <\/td>\n<\/tr>\n
66<\/td>\nBibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":"

Optical fibres. Reliability. Power law theory<\/b><\/p>\n\n\n\n\n
Published By<\/td>\nPublication Date<\/td>\nNumber of Pages<\/td>\n<\/tr>\n
BSI<\/b><\/a><\/td>\n2011<\/td>\n70<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"featured_media":247660,"template":"","meta":{"rank_math_lock_modified_date":false,"ep_exclude_from_search":false},"product_cat":[649,2641],"product_tag":[],"class_list":{"0":"post-247653","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-33-180-10","7":"product_cat-bsi","9":"first","10":"instock","11":"sold-individually","12":"shipping-taxable","13":"purchasable","14":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product\/247653","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media\/247660"}],"wp:attachment":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media?parent=247653"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_cat?post=247653"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_tag?post=247653"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}