expression of interest (eoi) - isro · 3. facility for designing, fabricating and qualifying of...

Expression of Interest (EOI)

Fabrication of Honey Comb Decks for

Launch Vehicles from Indian Work-Centre

Indian Space Research Organisation

Department Of Space

Government of India

Expression of interest

Table of Contents

Part I- Scope of Work

1. BACKGROUND

2. EXTENT OF WORK

3. STRUCTURES AND CRITICALITY

Basic construction of a honeycomb deck and realization strategy

Part II: Facility Requirements

1. HUMIDITY/TEMPERATURE CONTROLLED STORAGE FACILITIES.

2. MECHANICAL TEST FACILITY

3. FACILITY FOR DESIGNING, FABRICATING AND QUALIFYING OF

TOOLING FIXTURES AND TEMPLATES

4. MATERIAL CONTROL AND MANAGEMENT

5. OTHER MANDATORY FACILITIES

Part III: Applicable Documents

1. Applicable drawings for PSLV Honey Comb Deck Hardware- CCD/PSLV-68 Dt:

27-08-2015 (Issue-01)

[QMPG-CCD-DRG LIST-PUS-049; Dt: 03/09/2015

2. Process document for realization of metallic honeycomb sandwich deck plates

[VSSC/SDEG/HPDD/TM-02/2014; 29/05/2014]

3. Other applicable documents

Part I- Scope of Work

1. Background

In a launch vehicle, there are used many honeycomb deck plates of different size and

shapes. These deck plates are made out of aluminum alloy honeycomb core stuffed

with top/bottom plates. This is low weight- high strength constructions and that’s why it

finds applications in making aerospace packages platforms. This bonded metallic

honeycomb sandwich products are used as the platform on which, various electronic

packages, on-board computers, control and guidance systems as well as satellite and

payloads in the a launch vehicle. Realizing of such simple yet critical deck plates,

requires dedicated facility under organized set-up with all testing and qualifying

systems. With the increased demand of PSLV and GSLV, requirement of deck plates

has very significantly increased which is not actually being fulfilled with the existing

work-centres. Hence, to meet the huge demand for launch vehicles, Department is

willing to receive Expression of Interest from promising contractors to realize

Honeycomb Deck plates of aerospace quality.

2. Extent of Work

Each Polar Satellite Launch Vehicle (PSLV) requires 13 types of Honeycomb deck

plates of different shape and size. Whereas in GSLV, 7 types of deck plates are used.

These deck plates are of different thickness and size based on the application and

location. These are to be realized by bonding Aluminum skin sheets of AA 2014‐T6

material over Aluminum Honeycomb core using various Adhesive and potting

compounds and finally trimming to required size. The proposed work is for supplying 12

qualified sets of all required configuration for PSLV and at least 2 qualified sets for

GSLV flights every year with continued demand for 5 years or more.

The size of various configurations varies from sector dia 0.7M to 1.5 M (radial sector)

and thickness varies from 20mm to 110mm. For all different configuration of deck plates

and process plans for its realization, appicable documents may be referred. Raw

material being mostly aluminum alloys of aerospace quality, realization of such products

requires different advanced manufacturing processes at different stages.

3. Structure and Criticalities

A brief idea about the overall construction of a typical configuration and the critical

processes involved in the realization of deck plates with specific facility set-up required

is mentioned below.

Basic construction of a honeycomb deck



Various other configurations of Honeycomb structures

Structure Realization Strategy

� The performance of bonded metallic honeycomb sandwich products is highly fabrication

process sensitive and the process needs to be adhered with greatest care.

� An approved process document which describes the methods and practices involve

realization of metallic honeycomb structures shall be followed by the realizing agency.

� Design, realization and qualification of

the aluminum sheets and curing and bonding of decks shall be realized by the

prospective vendors.

� All AA components must

activities.

� Test coupons are prepared from the

extended portion as per drgs.

� Dimensional & geometrical parameter in

inspection equipments, 3D CMM

Various other configurations of Honeycomb structures:

Structure Realization Strategy:

The performance of bonded metallic honeycomb sandwich products is highly fabrication


An approved process document which describes the methods and practices involve

f metallic honeycomb structures shall be followed by the realizing agency.

Design, realization and qualification of templates, drilling and curing


All AA components must be Anodized for surface protection purposes before bonding

Test coupons are prepared from the actual flight deck plates by trimmed

as per drgs.

Dimensional & geometrical parameter inspection of final product

inspection equipments, 3D CMM, FBT equipment etc.

The performance of bonded metallic honeycomb sandwich products is highly fabrication


An approved process document which describes the methods and practices involved in

f metallic honeycomb structures shall be followed by the realizing agency.

curing plates for cutting


for surface protection purposes before bonding

trimmed-off from the

product using qualified

Part II: Facility Requirements

1. HUMIDITY/TEMPERATURE CONTROLLED STORAGE FACILITIES.

Room Conditions for adhesive bonding operations and post bonding processes,

storage of identified inserts, skin sheet, core and semi-finished deck plates while

fabrication): Environment should be contamination-free and should be controlled for

temperatures of 18 to 24°C, relative humidity of 40 to 65 % .

2. MECHANICAL TEST FACILITY

Strict compliance of raw material specifications, process control procedures, at every

stage of fabrication ensures suitability for good reproducible products. Various test

methodologies and detailed procedures of testing of Aluminium Skin sheets,

Honeycomb core and adhesives are to be followed. Work Centre shall generate and

maintain records and procedures in order to maintain traceability of raw materials,

process, coupons, tooling and instruments used during product realization. These

records shall be available for verification at any time. The tested coupons shall be

disposed only after VSSC review. All coupons shall have labels marked before

cutting and testing. Both sides of the lap shear coupons shall be labeled before

slicing.

3. FACILITY FOR DESIGNING, FABRICATING AND QUALIFYING OF TOOLING

FIXTURES AND TEMPLATES

Various steps are involved in this crucial phase of fabrication such as preparation of

core, preparation of skin sheets, preparation of inserts, preparation of adhesive

films, molding of panel, fabrication of test coupons, curing of the product, drilling and

potting of inserts, edge sealing of sandwich panel segments etc. These are

explained in detail in the process documents. Templates are prepared for curing and

drilling purposes and also to check the deck plates for proper alignment with the

interface. Surface of the templates are milled on both surfaces and sides to obtain

the correct dimensions. Holes are drilled on the templates for interfaces.

4. MATERIAL CONTROL AND MANAGEMENT

AA 2014‐T6 is used for making Aluminum skin sheets as well as Aluminum

Honeycomb core in HOBE form/ Expanded core form. Few examples of Potting

compounds, Adhesive film and inserts are given below for references; but for

detailed specification, process documents may be referred,

� Potting compounds:- Araldite-AV138IN, HV998;

� Adhesive film:- Redux 319A, 312;

� Aluminum inserts-Aluminum (B51 SWP/ AA6061 T6/AA 6351 T6);

� Primers- Redux 119, Redux 112;

� Helicoil- Stainless steel helicoils inserts (SS 304) and other various sealant.

All the above raw materials required for realization of honeycomb structures have to

be procured from reputed manufactures like M/s. Hexcell .

Specific storage condition is required for raw materials which is given in the process document. Specific requirements, if any, specified by the supplier of the raw material shall be implemented. 5. OTHER MANDATORY FACILITIES

Apart from above mentioned system, other important facilities like Clean Room for

carrying out bonding of Honeycomb decks, Chemical Etching, Surface Treatment

facilities are mandatorily required. Process equipments like autoclave, Potting Gun,

Fokker Bond Test equipment for NDT evaluation etc are also required.

Part III: Applicable Documents

Following process document and drawing list are applicable for PSLV Honey

Comb Deck Hardware realization.

1. Applicable drawings for PSLV Honey Comb Deck Hardware- CCD/PSLV-68 Dt:

27-08-2015 (Issue-01)

[QMPG-CCD-DRG LIST-PUS-049; Dt: 03/09/2015]

2. Process document for realization of metallic honeycomb sandwich deck plates

[VSSC/SDEG/HPDD/TM-02/2014; 29/05/2014]

Others applicable documents for quality control requirements are listed below:

1. General quality requirements and protocol for the realization of Launch Vehicle, light

alloy structures. MEE/QCI/43.86/14/2002 Feb.2002 (Issue-0)

2. Quality control requirements for storage, preservation and distribution of materials,

components and assemblies for Launch Vehicle Light alloy structures.

MEE/QCI/43.86/QCP/15/2002 Feb.2002 (Issue-0)

3. Quality control requirements for anodising aluminum alloy components for Launch

Vehicle structures. MEE/QCI/43.86/QCP/16/2002 March 2002 (Issue-0)

Note: All these documents shall be provided to the qualified party.