Relaxation in Bolted Thermoplastic Compositejoints

Horn, Walter J.; Schmitt, Ron R.

doi:10.2514/6.1993-1350

Cited by 10 publications

(7 citation statements)

References 3 publications

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“…Relaxation in bolted thermoplastic composite joints was tested by Horn and Schmidt [ 73 , 74 ]. Two graphite/thermoplastic composite materials were tested with matrix made of Dupont’s IM6/KIII and ICI-Fiberite’s IM8/APC(HTA).…”

Section: Viscoelastic Effectsmentioning

confidence: 99%

Mechanical Joining of Fibre Reinforced Polymer Composites to Metals—A Review. Part I: Bolted Joining

Galińska

2020

Polymers

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As the fibre reinforced plastic composites gain larger and larger share in industry, the problem of joining them with metal elements becomes significant. The current paper is the first part of the literature review, which gathers and evaluates knowledge about methods suitable for mechanical joining of composite and metal elements. This paper concerns bolted joining, because this method of mechanical joining is widely used for joining composite materials. The paper describes failure modes of bolted joints in composite materials, the influence of the bolt clamping torque, the clearance between the bolt and the hole and aging on the performance of the joint, drilling techniques used in composite materials in order to minimize damages, different fastener types, inspection techniques, and finally, the techniques that have been developed in order to improve the strength of the bolted joints in composites. Since the hole drilled in a composite material in order to perform bolted joining is a weak point of the structure, those techniques: bonded inserts, titanium foil internal inserts, fibre steering, additional reinforcement, and moulded holes, mainly aim to improve the strength of the hole in the composite. The techniques have been discussed in details and compared with each other in the summary section.

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Section: Viscoelastic Effectsmentioning

confidence: 99%

Mechanical Joining of Fibre Reinforced Polymer Composites to Metals—A Review. Part I: Bolted Joining

Galińska

2020

Polymers

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“…The cyclic loading will cause the bolted joint to be self-loosened Horn and Schmitt [30] Relaxation in Bolted Thermoplastic Compositejoints The cyclic loading will cause fretting wear the result in the reduction of clamping force Liu et al [31] Study on self-loosening of bolted joints excited by dynamic axial load…”

Section: Screw Self-loosening In Bolted Jointsmentioning

confidence: 99%

“…They found out that the fretting wear can be the source of the self-loosening of the bolted joint under transverse cyclic loading without any rotation of the nut. The fretting wears lead to steady reduction of the clamping force as the number of loading cycles increase [30]. In Liu et al [31] papers it is stated that when bolted joints are exposed in a vibrational environment the main failure mode of the bolted joints is the self-loosening.…”

Section: Ricci Et Al [35]mentioning

confidence: 99%

Screw-Bone Implant Loosening: Complication, Cause and Assessment

Ghani¹,

Hassan²,

Daud³

2018

IJET

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Bone fracture has become more common in this era of vehicular modernization. Internal fixation has been used in the treatment of such cases. The use of screw and plate in internal fixation has been proven to provide more stability to fracture to promote better healing. The use of screw also carries certain risk such as self-loosening that can cause non-union and prolong healing. The complication of selfloosening is studied to comprehend the danger of self-loosening in screw-bone implant. The review on self-loosening in bolted joint is done in this paper to gain better understanding on the nature of self-loosening phenomena. The factor that affects the screw selfloosening in bone is further studied in the screw-bone implant environment. The identification of the screw loosening can be done with radiography, CT scan, MRI and ultrasound. This article have done a brief review on the complication of screw self-loosening, the cause of screw loosening in bolted joint and screw-bone implant and the assessment of screw loosening done by ultrasound and radiography.

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“…Based on the assumption of time hardening, that is, assuming that only transient creep stage exists during the whole creep behavior, Shivakumar and Crews 17 developed a quantitative expression called the Shivakumar-Crews model (S-C model) which relates the non-dimensional preload loss versus time, and includes the effects of temperature and humidity. It has been used for analyzing short-term relaxation and longterm prediction by many experts such as SchmittRon 5 , Caccese et al, 6 Horn and Schmitt, 18 and Thoppul et al 19 Taira 33 summarized numerous phenomenological models, wherein Hook-Norton model (H-N model) was specially mentioned. The H-N model was derived under the assumption of strain-hardening, that is only the steady creep stage was considered during the derivation.…”

Section: Introductionmentioning

confidence: 99%

Time–temperature-dependent response and analysis of preload relaxation in bolted composite joints

Xiao

Yang

2018

Journal of Reinforced Plastics and Composites

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Although mechanically fastened joints are generally considered a mature technology, significant problems still exist with their use, among which the preload loss in pretensioned bolts is a major one. This paper has investigated two key issues in structural durability design for mechanically fastened composite joints, i.e. temperature–time-dependent behavior for viscoelastic preload relaxation and prediction method for its long-term performance. Towards this purpose, a two-phase experimental program was conducted consisting of short- and long-term joint relaxation tests. Phase I monitored the short-term fastener preload relaxation (up to 36 h), with a special self-made bolt strain sensor. Phase II utilized the time–temperature superposition principle to establish a method of using short-term relaxation curves to construct the long-term master curve (accelerated test). It was found that there was a significant loss of bolt preload when temperature and initial preload increased, and the relaxation rate of composited joint was much larger than that of the metallic joint. Based on the strong temperature dependence of bolt relaxation, accelerated characterization was conducted for long-term behavior. Furthermore, to quantitatively relate the relaxation data to a model equation, a new preload prediction model was developed based on the creep total-strain theory. Comparisons of the prediction model and accelerated test results indicated that the improved model provided better accuracy than existing models such as Shivakumar–Crews’s and Hook-Norton’s models for describing the long-term preload behavior.

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Relaxation in Bolted Thermoplastic Compositejoints

Cited by 10 publications

References 3 publications

Mechanical Joining of Fibre Reinforced Polymer Composites to Metals—A Review. Part I: Bolted Joining

Mechanical Joining of Fibre Reinforced Polymer Composites to Metals—A Review. Part I: Bolted Joining

Screw-Bone Implant Loosening: Complication, Cause and Assessment

Time–temperature-dependent response and analysis of preload relaxation in bolted composite joints

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