Methods of test for strength and stability of settees and benches, Part 1: Strength

IS 12674 Part 1 - Scope: Key Specifications & Tables

The standard defines test levels and procedures for furniture strength and durability, focusing on static, fatigue, impact, and drop tests.

Test Levels & Load Specifications (Table 2 Summary)

Furniture Application vs Test Level (Table 4)

Purpose of Tests (Table 1)

• Static load tests: Basic strength, damage initiation

IS 12674 Part 1: Referenced Standards & Key Tables

Referenced Indian Standards (Clause 2.1)

• IS 287:1973 — Maximum permissible moisture content of timber for various uses.
• IS 809:1970 — Specification for rubber flooring materials.

Furniture Test Levels & Applications (Table 4, Clause 1.2)

Summary of Test Procedures & Loads (Table 2, Clause 8.7.1)

IS 12674 Part 1: Principles of Testing - Key Points

1. Types of Tests & Their Purposes (Clause 3.1.1, Table 1)

2. Test Levels & Parameters (Clause 8.7.1, Table 2)

3. Impact Test Principle (Clause 3.4)

• Tests simulate rapid loading events.
• Assess residual and impact strength.
• Important for durability under occasional misuse.

Summary Diagram of Test Interrelations

graph LR
A[Static Load Tests] --> B[Fatigue Tests]
B --> C[Impact Tests]
C --> D[Drop Tests]
A --> D

Use these tables and principles to select appropriate test levels based on product category and expected service conditions.

IS 12674 Part 1: General Requirements for Tests

Key Tables & Test Summary

Table 1: Test Types & Purposes

Table 2: Test Levels & Parameters

IS 12674 Part 1: Inspection Before and After Testing

Key Specifications (Clauses 5.1 & 5.1.1)

• Before Testing:
  • Thorough inspection of all articles.
  • Note defects in members, joints, attachments.
  • Complete dimensional check on parts prone to permanent deformation.
• After Testing:
  • Thorough re-inspection immediately after tests.
  • Note any new defects or changes since initial inspection.

Important Tables for Test Levels & Loads (Clause 8.7.1)

IS 12674 Part 1: Test Equipment and Setup - Key Specifications

Test Levels & Forces (Table 2 Summary of Test Procedure)

Test Equipment Setup Guidelines

• Load Application: Use calibrated hydraulic or mechanical actuators capable of applying static and cyclic loads as per test levels.
• Impact Tests: Use drop-weight impact testers with adjustable drop heights

IS 12674 Part 1: Determination of Seat and Back Loading Points

Key Specifications & Procedure

• Double Back Loading Pad (Clause 6.13):

  • Two rigid rectangular pads: 200 mm height × 250 mm width
  • Faces curved with convex cylindrical radius = 450 mm
  • Front edges rounded with 12 mm radius
  • Adjustable distance between pads to align centers over back loading points

• Loading Point Determination (Clause 6.3 & 7):

  • Use a template (Clause 6.3) positioned on the seat centerline, pushed rearwards to match seat shape.
  • Template set at 90° angle (Fig. 3).
  • Mark loading points on seat and back from template.
  • Seat loading pad mounted first on seat plane at seat loading point, then on front edge.
  • Apply downward force V (from Table 2) 10 times per position.

Loading Pads Dimensions (mm)

Test Reference

• Clause 8.1: Seat and Back Static Load Tests use these loading points and pads.

Summary Diagram (Loading Point Setup)

graph LR
A[Template (6.3)] --> B[Position on Seat Centerline]
B --> C[Push Rearwards to Match Seat Shape]
C --> D[Mark Seat & Back Loading Points]
D --> E[Mount Seat Loading Pad at Marked Points]
E --> F[Apply Force V (Table 2) 10 Times]

This procedure ensures accurate and repeatable load application points for static load testing of chairs per IS 12674 Part 1.

IS 12674 Part 1 — Key Test Procedures Summary

Test Levels & Forces (from Table 2)

IS 12674 Part 1: Criteria for Passing Tests

Key Specifications & Test Levels (from Table 2)

Summary of Criteria for Passing

• Load Tests: Must sustain specified static forces without failure or permanent deformation.
• Fatigue Tests: Must endure the specified number of load cycles without structural damage.
• Impact Tests: Must resist impact at specified drop heights or angles without loss of function.
• Drop Test: Must survive drop from specified height without failure.

Additional Notes (Clause 8.4)

• Document any non-standard forces applied.
• Clearly state pass/fail status.
• Report any deviations from standard procedures.

Purpose of Tests (Table 1)

• Static Load Tests: Assess basic strength and damage initiation.
• Fatigue Tests: Evaluate service durability and damage propagation.
• Impact Tests: Measure residual strength and resistance to misuse.

flowchart TD
    A[Start: Test Setup] --> B{Apply Static Load}
    B -->|Pass| C{Apply Fatigue Load}
   

IS 12674 Part 1 — Test Report Key Formulas, Tables, and Specifications

1. Pass Criteria (Clause 9.1)

• Article passes if:
  • No defects observed (Clause 5)
  • Backforce ≥ 410 N (Clause 8.1.2)
  • Meets product-specific requirements

2. Test Types & Purposes (Table 1, Clause 3.1.1)

3. Test Levels & Parameters (Table 2, Clause 8.7.1)